BBC science producer Martin Redfern is spending a month in the Antarctic reporting on International Polar Year. You can follow his exploits on this page.
25 FEBRUARY - THE BIG LIFT
After the long light evenings south of the Antarctic Circle, it seems strange to see the nights drawing in, and the "darken ship" command come as early as 9pm.
By dawn, the rocking motion of the ship has subsided; we are in the calm, misty waters of Port Lockroy again. Is it really three weeks since we were last here?
In the end, every last matchstick is removed from the mountain
It seems as if nothing has changed. Cloud still hangs over the mountains, penguins cavort through the sea, and an old Russian cruise ship is anchored nearby.
No doubt the penguin colony stills smells the same.
But we are soon on our way. We have to go right round the northern tip of the Antarctic Peninsula, to James Ross Island, a huge ancient volcano that is the principal destination for this entire voyage.
Two months ago, in difficult weather conditions, the helicopters from HMS Endurance landed a team of scientists and drill technicians there with 20 tonnes of equipment.
Over the next few days it is our job to collect them again - if the weather allows.
To our relief, the next morning sees sunshine streaming in through my porthole, and the sea is calm.
It's going to be a busy day, as the forecast says the fine weather will not hold.
Both helicopters have been fitted with winches to take big loads slung underneath. They begin ferrying Royal Marines up the mountain to help the scientists pack up; we are close behind them.
Mount Haddington is a wide, ice-covered mass more than 5,000 feet (1,500 metres) high; the closest thing I have seen to the wide, white wastelands of central Antarctica.
Vicious winds can race across the heights, biting through the last layer of thermal underwear, and sculpting the icy ground into sastrugi, ridges of snow that are only centimetres high but which seem perfect icy models of the canyons and badlands of the Wild West.
Rob Mulvaney and his colleagues have been living up here for the past two months in pyramid tents not very different from those used by Captain Scott a century before.
But they have brought luxury with them as well, with a generator, hot shower and even a fresh bread-making machine in a larger social tent.
Their reason for being here has been to drill into the ice.
After a slow start due to bad weather, the project has gone surprisingly smoothly and they reached the base of the ice, more than 360 metres beneath us, two weeks ahead of schedule.
Robert and Sam have had a few simple luxuries during their stay
Since then, Twin Otter planes from Rothera have been landing on the ice and ferrying the ice cores out, lightening the load that we must carry to HMS Endurance.
When analysed back in Cambridge, the composition of the ice and the air bubbles trapped within it should reveal how the climate here has changed over more than 30,000 years.
That's of special interest today because, unlike the centre of the continent, the Antarctic Peninsula is warming fast, perhaps 3C in the last 50 years.
The question is, has anything like this happened before? Is this part of a natural cycle or is it an early sign of warming resulting from human activity?
The immediate issue however is to remove all the equipment, tents and people safely back to HMS Endurance before the weather changes.
So, after conducting interviews and taking photos, we pitch in to help pack up.
I end up helping to dig out the toilet tent!
The edges have been weighted down with snow to hold back the wind, and it has now mostly turned to ice which must be removed with spades and hammers before we can pack up the tent.
Tents on Mount Haddington look like a scene from a polar legend
All the time, helicopters are buzzing to and fro carrying slung loads of timber and boxes in nets.
The pilots and observers have worked a long hard day, but in the end every last matchstick is removed from the mountain. The only sign that this has been home for two months to seven people and a major scientific project are a few trenches and footprints in the snow.
Back on ship, the captain is hosting an impromptu drinks party on the helideck.
To get as close as possible to Mount Haddington, Endurance has sailed into Croft Bay, the flooded crater in the middle of this volcanic island. We are surrounded on three sides by spectacular cliffs and tumbling glaciers.
This clearly is a special place in the heart of our captain, and I can share the sentiment, particularly as I watch the sunset turn the snow fields above to pink.
But a shard of my heart still lies among the windswept sastrugi 5,000 feet above us.
22 AND 23 FEBRUARY - CROWE'S NEST
Down to the Bonner marine biology lab this morning to see how Antarctic sea creatures cope with the cold.
Melody Clark has been working on fascinating research into the genes they use. Some are able to withstand freezing down to -40C or even colder.
A call goes out - "orcas on the port bow!"
They do so by removing almost all the water from their cells so that ice crystals cannot form inside and burst them. That leaves them with problems very similar to those created by drought.
During the long Antarctic winter, most of the marine organisms slow down their metabolism almost to a standstill.
The Antarctic cod (not a true member of the cod family) doesn't exactly hibernate, but it becomes very drowsy, stops feeding, and its heart rate slows right down.
Lloyd Peck knows this because he has fitted heart monitors to free-swimming cod off Rothera.
HMS Endurance is back at the quayside having spent the last couple of days sailing in the area with VIP guests.
Just as I am about to sit down for a cup of coffee, a call comes over the radio that she will depart at 11am rather than midday, so I race to get my bags and climb aboard.
As I do so, a call goes out - "orcas on the port bow!" I race up on deck just in time to see a small pod of killer whales pass close to the ship.
We head north towards the narrow channel that separates Adelaide Island from the Antarctic Peninsula.
A helicopter flies ahead to check for icebergs, then returns - and suddenly we're turning around.
The channel is blocked by ice. So we have to circle round to the west, where the sea gets ever rougher.
Getting on board ship impedes morning coffee at Rothera base
By the next day, it has built to sea state seven, which means that the waves are seven metres high.
Some say they peaked at 10 metres and the wind rose above 65 knots, the threshold for hurricane force.
Fortunately, although it affects my ability to stand upright it does not seem to affect my appetite for dinner or for watching waves crash over the bows. The most serious casualty is the wardroom teapot which slides off and smashes.
Those of us not confined to bunks spend a bizarre afternoon watching both of the Bridget Jones films.
In the evening, the entertainment is more appropriate, the film of Master and Commander. When I see the conditions under which sailors operated 200 years ago, out on an open deck, climbing the rigging or trying to sleep in the spaces between the cannon, I realise I have no grounds for complaint about the accommodation aboard Endurance!
21 FEBRUARY - UP, UP AND AWAY
Another early start today, this time to catch the still air of morning above the Rothera Research Station.
As we cross the busy runway, a couple of Twin Otter planes are already preparing for flight. This crossing has what must be the only set of traffic lights in Antarctica.
At the back of the aircraft hangar we find Jonathan Shanklin, a veteran of Antarctic climate research.
He is preparing a radiosonde for launch under a helium filled weather balloon; something he does three times a week, to contribute to weather forecasting worldwide.
Antarctic radiosondes contribute to global weather forecasting
The sonde is calibrated, connected to its battery, and the telemetry tested.
Then Jon fills the big white balloon with helium, hangs the sonde underneath and takes it outside.
Upon release, it rises quickly, at about four metres per second. By the time it reaches the first cloud layer, 300 metres up and 75 seconds later, it's scarcely visible.
At ground level, the balloon is almost two metres across. By the time it bursts, more than 20 kilometres above us, it will be the size of a double-decker bus, having expanded in the lower pressure of the upper atmosphere.
But by then its work will be over. It will have sent back a profile of the lower atmosphere at this particular place and time to add to all the others around the planet that are fed into forecasters' computers.
We go on to talk with Jon about his long career with the British Antarctic Survey.
He was one of the scientists who, back in the late 1970s, first drew attention to the hole in the ozone layer. A series of patient measurements from the UK's Halley and Faraday research stations, the latter now Ukrainian, spotted how high, cold ice clouds in the Antarctic spring produced conditions in which CFCs released by human activities could react to destroy ozone.
So wide was the hole that US scientists using satellite measurements thought there must be a calibration error and disregarded it.
Today, the use of CFCs has all but stopped; their concentration in the stratosphere has levelled out and, it is hoped, will soon start to fall. The next big challenge in atmospheric science, global warming, will be harder to correct.
Jonathan Shanklin is passionate about our responsibility to our planet and its natural resources.
While he was at the Halley base, he had to shovel snow into a melter every day to make water.
"It's amazing how much snow you have to dig to get a shower out of it," he says.
"If everyone had to get their own water rather than just turn on a tap, you'd soon realise that water was a precious commodity."
20 FEBRUARY - NEW ARRIVALS
In spite of the festivities the night before, I am up early today to walk around Rothera point.
There is only a gentle well in the iceberg field to the north, but it's enough to make an incredible musical sound as the smaller fragments of ice rise and fall, clanking against one another like the notes of a glockenspiel.
Young fur seals enjoy play fighting
The docile Weddell seals we saw a fortnight ago have been replaced by more dog-like fur seals. These are young males and they're practising play fighting between each other and growling and barking at me as I pass by. But it's all bluff (I think).
If they think I am not watching, one will approach me, but as soon as I turn towards it, it pretends it was doing something completely different. Their rich brown fur and incredibly long moustache whiskers glisten in the morning sun.
After breakfast, we hear that a diving boat is about to set out and has one spare place on board. As always, Gabrielle quickly volunteers and is fitted out in a survival suit.
I find it amazing to think that the marine biologists go out in a rigid inflatable boat two or three times a week, sometimes even in winter, for dives underwater and to check out the marine organisms. Of course they have state-of-the-art dry suits and diving equipment, but it chills me just to think about it.
A few years ago, there was a tragic fatality when a diver was pulled down by a leopard seal, so there is always a close watch kept for these most aggressive of the seals.
Meanwhile, I have the luxury of a good internet connection and access to my e-mail account. I can also set up my satellite link on a stable platform and send good quality audio reports to my colleagues in London on Science in Action.
Adelie penguins return to land to moult
News just in that the Pine Island Glacier is accelerating seems of international importance so I send a report to World Service news as well.
Both the Rothera base and HMS Endurance have important guests arriving on the Dash 7 flight from the Falklands today.
From the Royal Navy comes Admiral Sir Mark Stanhope, Commander in Chief of the Fleet. The initials of his title, CinC, Fleet, have the unfortunate pronunciation sink fleet! He and other senior figures are piped aboard Endurance.
The captain is keen to impress, not least because our ageing vessel will soon be due for replacement.
On the same flight is the head of the British Antarctic Survey, Nick Owens, and three Canadian officials who are signing a memorandum of understanding between the UK and Canada concerning polar research. It should lead to greater cooperation and perhaps access for British scientists to Canadian Arctic facilities, and vice versa.
While the VIPs get shown around, I get the chance to go boating. Once suited up, we climb into one of Rothera's rigid inflatables, with twin 40 horsepower outboard motors.
It takes little more than 15 minutes once we have emerged from behind the red bulk of HMS Endurance to cross the bay and reach Lagoon Island. It takes only slightly longer for the ice in my ear to thaw!
Lagoon Island is low, with gently sloping beaches and shallow water. We wade ashore and it is a tribute to artificial fabrics that my feet are still toasty warm. Immediately, we are greeted by the local inhabitants.
An elephant seal basks in sunshine
There's a large group of elephant seals, mostly females and immature males, but also with a couple of adult males with their huge blubbery noses. They seem quite unconcerned by our presence, and continue snoring, grunting and scratching themselves with surprising precision. One does head off into the sea, but it is only to check out our boat, perhaps to see if it will play.
Here too are fur seals and a single Weddell seal. There's also a small group of Adelie penguins that have come ashore to moult. Some look decidedly scruffy and are having a "bad feather day". Others, later in the moulting process, seem newly laundered in freshly pressed black and white.
19 FEBRUARY - DOWN THE CREVASSE
In the afternoon, at last in sunshine, the distant mountains of Adelaide Island emerge from the horizon and we sail round to the Rothera Research Station again.
The 27 tonne crane has been repaired, so we can launch one of the ship's small boats, Nimrod, to join Eddie Shackleton, which has been in use for a boat camp since we were last here.
HMS Endurance will be entertaining some VIP visitors over the next few days, so I take the chance to have a few nights on land, in a bed that doesn't move. I'm sharing with a big lad called Lenny - though I don't get to meet him for a couple of days!
Festivities aboard HMS Endurance
He's working with Morrison Construction, putting the finishing touches to a big new building at the base, using the long daylight to work from 6.30 am until 9 pm.
Today, there is a big event at Rothera - the "Winter Olympics" - with teams and individual competitors from the British Antarctic Survey and HMS Endurance competing in a variety of snow sports, from serious skiing to some lethal-looking homemade sledging and even ice sculpture.
As Olympic preparations get under way, Athena, Gabrielle and I, under the jovial but watchful care of field assistant Adam, head for a crevasse in the glacier that overlooks Rothera. With us is Julian Scott, recently returned from 97 days on the Pine Island Glacier. This is going to be a location interview with a difference!
A crevasse in the glacier that overlooks Rothera
There's a safe track across the glacier marked out with flags. To my untrained eye, there is no difference in the ice just above it, except for a small hole, less than a metre across; no clue that it's the access point to a vertical gash 100 metres long, the rest roofed with a fragile snow layer.
We rope up, put on crampons, and half climb, half abseil down into the sloping shaft. Just a few metres down it opens out into a winter wonderland, festooned with icicles. There is no direct sunlight, but the whole crevasse is glowing with a rich light of, well, ice blue.
So translucent is this frozen palace, so blue the ice-filtered sunlight, that no one will believe I haven't retouched my photos.
And all the time, a faint drip, drip, drip, as water that melted higher up runs down to re-freeze on the stalactite icicle fairyland.
But some of the older icicles seem bent and buckled, and the occasional sharp "crack" reminds us that we are inside a glacier that's on the move, albeit slowly.
The Pine Island Glacier is on the move too, and considerably faster. Julian Scott has recorded a 7% acceleration in the past season and is trying to determine the cause. It could ultimately lead to the collapse of the biggest glacier in Antarctica, with consequences for sea level worldwide.
Not being much of an Olympic athlete myself, I return to HMS Endurance to see if it will be possible to record a few minutes of the live band at the party tonight.
Martin on a skidoo
I quickly get conscripted as assistant sound engineer. I'd do a better job with the gear back home, and the Rothera house band "Lead Filled Snowshoe" isn't quite as polished as when they played at Nunatak in the Live Earth concert six months ago, but they make a good sound with Rothera's French chef Cyril on vocals.
There is an open air Antarctic barbecue on the quarterdeck, a bar and band in the junior mess, and Endurance is firmly tied up to land that doesn't pitch and roll. A good night!
17 FEBRUARY - HIGH ON HELIUM
We're up on deck to see a humpback whale breaching, propelling its huge body out of the water.
Martin basks in the majesty of Overton Peak
Some say they do it to shake off parasites, but I suspect it's just for fun.
At first today, there's low cloud and poor visibility, but it seems to be improving; so the first two sets, or sticks, of passengers don their goon suits and prepare.
So as not to look too ambitious, only three sticks are officially listed, each to a different location.
Science and safety are the priorities, but my presenter Gabrielle is listed, so I give her a quick lesson in how to use the sound recorder.
I'm just listed as a footnote.
The first stick takes off, only to land again seconds later, complaining of a burning smell.
The helicopter is shut down and checked out. To everyone's relief it's a minor problem and they're soon on their way again.
Bit by bit, visibility improves, and the two Lynx return for more passengers. Eventually my stick is called.
It's a wonderful flight, low across the bay, between spectacular icebergs, over an ethereal layer of mist.
Wherever the floating ice is low enough, groups of crabeater seals are lazily rafting.
Then there is a steep climb as the Sun comes out, to level ground with patchy snow, near the summit of Overton Peak.
The first impression is of walking on cinders. Overton Peak is an old volcano - and not that old as volcanoes go. Maybe two million years.
By the time I arrive, Gabrielle has done most of the recording and geologist Phil Leat is in his element.
Many - perhaps 10% - of the cinders are a dull green colour, standing out against the bulk which are a dark reddish black.
The green ones are also dense and break open to reveal what looks like green-tinted demerara sugar.
This is olivine, one of the principal minerals of the Earth's mantle, torn up in erupting magma and spewed out on the surface, 40km above its natural home. These are the mantle "xenoliths" that Phil has been seeking.
There's a broad grin on his usually shy, serious and focused face as he fills a small sack with them.
They should carry the chemical clues to their origin, as well as atoms of helium-3 from cosmic bombardment that Jez Everest will be able to use to measure how long ago the ice first exposed these rocks.
Then there is just time to struggle up the steep cinder slope to the nearby summit and admire the view.
Once I get my breath back, I listen. An unfamiliar sound: total silence; no voices, no distant traffic, not even the squawk of a skua.
Back at the helicopter, flight commander Colin Simpson is photographing a large cuddly toy in the snow. Who says you don't get polar bears in Antarctica?
I can't believe my luck when he says there is just time for another stop. On the way we locate Jez and Nick with field assistant Roger Stilwell.
They've climbed high on Mount Holt to get samples from different altitudes. Colin's observer, Jane, is looking for somewhere where it will be possible to lift them off. She spots what looks like a minute patch of snow at the top of a cliff.
The rocky promontory where we land is also tiny; the helicopter rests on the soft snow without putting its full weight down as we jump out. This headland has no name, so we call it Convey Point.
Crabeaters have become a familiar sight
Pete Convey is almost as excited as Phil was, this time over a few tufts of grass in a mossy hollow and clumps of another small plant, a pearlwort called Colobanthus. These are in fact the only two flowering plants found on the Antarctic continent and both have set seeds.
This could be a southerly record.
Soil scientists David Hopkins and Paul Dennis are also happily filling sample bags from this lush location. Pete digs out a thick section of moss, possibly representing many centuries of growth and perhaps sheltering a menagerie of tiny bugs for him to study later, under the microscope.
This whole, surprisingly lush ecosystem must gain its nutrients from penguins and the colony of skuas which wheel and cry overhead, dive-bombing us if we go too close to their large fluffy chicks.
But visibility is failing now and it's starting to snow quite heavily. We race back to the set-down site, clamber once more into the stifling but warming goon suits and drag ourselves and our equipment against the blizzard of ice blown out from the spinning helicopter rotors that are our hoist to warmth and safety.
16 FEBRUARY - SYMPHONIA ANTARCTICA
By dawn we are close to the southern part of Alexander Island again.
It's a very musical region. The Beethoven Peninsula is drained by the Palestrina Glacier.
Just across the Bach ice shelf from Berlioz Point lies the Monteverdi Peninsula, overlooked by the Staccato Peaks.
It is hard to convey the full beauty of this place
The frustrated geologists gaze wistfully through binoculars towards the Elgar Uplands. But there is no going ashore today.
Instead, we're working our way north along Alexander Island. I call it an island, but it is almost twice the size of Wales.
Eventually, we reach Lazarev Bay.
The Captain is cautious. These waters are completely uncharted and there are ominous looking rocks and grounded icebergs, suggesting shallow water.
Slowly, HMS Endurance edges forward, sailing to and fro, using sonar to map out a safe box in which to settle for the night.
THURSDAY 14TH FEBRUARY - ROUGH LOVE
As soon as I awake, I can feel from the swaying motion that it's not looking good for going out in small boats.
Opening the shutter on my porthole confirms this - instead of calm, iceberg-strewn inshore waters, there are high, white wave crests and no land in sight.
As waves crash over the bows of the ship, I have to hang on to stand up, watching them from the comfort of the wardroom
A wave passes along the side of the ship, and for a few seconds, peering through the porthole is like looking into churning washing machine.
The seven am situation report is piped over the loudspeakers; a north-westerly gale has been packing icebergs into the bay, running the risk of trapping HMS Endurance.
The captain has decided that we must abandon hopes of geology on the "English Coast", and head across the Bellingshausen Sea to seek shelter near the Beethoven Peninsula on Alexander Island.
Like so many decisions resulting from changing conditions, it is a disappointment, but absolutely the right call.
Officer of the Watch Cheney Dyer rounds off the report with characteristic cheerfulness: "This morning's breakfast specials are porridge and black pudding. That is all."
It's also Valentine's Day. Heart-shaped chocolates have appeared in the wardroom, and Athena from the British Antarctic Survey and my presenter Gabrielle have been busy making little pink cards with lipstick kisses.
The Bellingshausen Sea in a gale is spectacular. As waves crash over the bows of the ship, I have to hang on to stand up, watching them from the comfort of the wardroom.
The running machines in the gym in the hold have become staggering machines, and those of a sensitive disposition have retired to their bunks.
Outside, in the driving snow, white birds swoop and glide with easy grace - snow petrels making use of the sheltered side of the ship to pick krill from the waves.
A solitary black browed albatross slices through the storm, without even needing to flap its wings, seeming to pivot on a wing tip, inches above the five-metre swell.
WEDNESDAY 13TH FEBRUARY - DELAYED BY PENGUINS
A fine start to the day, and conditions look promising for an expedition to Mount Sims, a key target for the scientists.
It's a long flight for the helicopters (romantically named 434 and 435), so it's an early start and the commands "action 434" and "action 435" come close together so they can fly as a pair.
The voyage will result in maps being redrawn
This should be an important day for the geologists.
The so-called English Coast is remote, mountainous and hard to reach. Few geologists have ever visited it
Mount Sims should yield volcanic rocks that may contain nodules of rock from the Earth's mantle, called xenoliths, giving clues to the breakup of the Gondwana supercontinent to create Antarctica, and to more recent volcanic rifting.
The rocks have also been scoured by ice, and by measuring how long they've been exposed to cosmic rays it should be possible to sort out how and when the ice retreated to its present position.
Each Lynx helicopter carries a pilot and an observer. With all the necessary survival equipment, that only leaves room for three passengers.
For safety, civilian scientists must be accompanied by a field assistant, the naval geodetic teams by a marine.
The geologists have come for their rock samples
The first priority is to get the geologists to Mount Sims; we are due to follow later.
We wait. And wait.
Eventually, we hear returning helicopters. But they are not returning for us; the frustrated geologists are still on board.
There's a large penguin colony at the planned landing site, and nowhere else flat enough to land. The only hope is to sail round much nearer the island and land in the rigid inflatable boats.
But that's a day's sailing away, and storms are forecast.
TUESDAY 12 FEBRUARY - THE DEEP SOUTH
We've had three days at sea, heading ever further South.
The Captain on HMS Endurance, Bob Tarrant, has decided that it would not be time-effective to try to reach Thurston Island.
Satellite images show a build-up of sea ice, so we might spend a week trying to get close and still not make it. Or worse, get stuck.
But that means we've more chance of getting the scientists into sites on Alexander Island and around the Ronne entrance.
The Ronne entrance marks the junction between the Antarctic Peninsula and the bulk of Western Antarctica, and the limits of the sea ice between Alexander Island and the mainland.
At 73 degrees South, it's as far as we can get and an exciting target for all the scientists.
We've had three days of watching from the wardroom, pacing the monkey deck, practising abseiling down the front of the ship and - for Adam, one of our more enthusiastic field assistants - abseiling down from the bridge to clean the windows!
One way to keep the windows clean
We've ridden out a storm with 40-knot winds, and the icebergs have got bigger and more numerous.
Last night they were particularly beautiful in the evening light. Now the waiting is almost over and we're scheduled to join the scientists on Eklund Island.
We've become used to seeing Weddell and crabeater seals on low icebergs; even the occasional minke whale, along with skuas and snow and Antarctic petrel. But we've had a real and unexpected treat this morning.
I missed the first call of "penguins on the port bow". By the time I got on deck they were Lowry matchstick penguins in the distance. But still bigger than Adelie penguins, and you don't get kings this far south.
I went to my cabin to change into warm clothing for our outing, only to see a single emperor penguin drift past my porthole on a small piece of ice. By the time I grabbed the camera and reached the deck, there were more.
One iceberg with two seals and 10 emperors! I didn't think they were found here. Nor did anyone else we can contact.
Rothera is home to about 120 scientists during the summer
Later, we saw a group with four big fluffy chicks. If they are breeding here it constitutes a colony, possibly one that's new to science.
This time the helicopters are flying in pairs. We have to go inland over the ice shelf, and one can act as search and rescue for the other in an emergency.
The first flight is for reconnaissance, then the geologists go in with three Royal Marines who are setting up geodesic survey points. Then it's our turn, along with soil scientists and a biologist.
We witness what could be a colony of emperor penguins
This part of Eklund Island is low and gently sloping, with a few rocks smoothed by ice, sticking through the snow.
Phil Leat, a geologist from the British Antarctic Survey, tells me it's 130 million-year-old granite, cut by dykes of dark rock from the roots of a later volcano.
This stretch of coast is near to the last split in the ancient supercontinent of Gondwana, from which New Zealand drifted away to leave Antarctica as it is today. But there are signs of more recent rifting too. Perhaps it will split again.
Another team of glacial geologists from the British Geological Survey in Edinburgh are also taking samples - with hammers and a petrol driven rock saw. They are after slices of the top five centimetres of the rocks for a technique called cosmogenic dating.
The surface of the Earth is constantly bombarded by cosmic rays.
The impacts create new sorts of atoms - isotopes - in the minerals in the rock. But cosmic rays don't penetrate far through rock or ice. So, if you have a fresh surface, ground down by ice, the isotopes only begin to accumulate when the ice retreats. Measure the isotopes and you have the age when the ice melted.
There's even life here! Wherever a rock sticks out above the snow, there are lichens.
Algae and mosses follow the crevices, perhaps with nematode worms and mites that will only be revealed under the microscope. Everything is tiny - anything that lifts more than a few millimetres from the rock will get frozen or blown away.
Endurance takes a well-earned rest at Rothera
This is life at the limits; but the soil scientists still hope to find a functioning bacterial ecosystem in the tiny pockets of earth.
Back on the bridge of HMS Endurance we watch as hydrographers conduct what is called swath bathymetry, sending out a wide fan of sonar signals to reflect off the sea floor.
A computer produces a plot of the seabed in three dimensions and it is obvious that there are long grooves gouged in it by ancient ice that once reached this far out to the sea.
When we look at the track of our ship over the previous few hours, superimposed on the best existing chart, it seems as if we have sailed a full eight nautical miles into the ice shelf. The maps will need updating; this section of the ice shelf retreated more than a decade ago.
FRIDAY 8 FEBRUARY - ROTHERA POINT
Up early today - hardly first light as it hardly gets dark, but at 7am there is a special quality to the light.
Today it's crisp low sunlight on the sparkling sprinkling of last night's snow, with a backdrop of dark clouds to highlight the radiant icebergs in the bay.
Martin and Gabrielle field questions from UK radio listeners
Rothera Point is an easy 40-minute stroll along the beach around the rocky promontory, just the job to freshen up for breakfast.
The "bergy bits" of shattered ice floating in the bay make gentle clunks and clinks as they jostle in the soft swell.
Picking my way around the rocky shore I almost trip over one inflated rubber boulder that turns out to be a Weddell seal. These are the yellow Labradors among seals - fat and friendly. It scarcely bothers to open an eye or raise its head.
Just round the corner there's a big, fluffy, fully grown penguin chick, with one parent. There are Adelie penguins - my first of the true Antarcticans, not found far away from this great white continent.
After a quick breakfast in Rothera's comfortable dining room, it's back to HMS Endurance for departure. Except that it isn't. The poor engineers have been up all night fixing the starboard engine. It's all repaired, but the oil is so cold it won't refill quickly, so we've another day at the research station.
We are already booked on a helicopter flight, which now departs from Rothera's runway. We've no destination, just recording some linking narration against the roar of the rotors.
One of the "beasties" from the Antarctic waters
It might seem an extravagance for radio, but there is no substitute for the vividness, accuracy and honesty it lends to reports. We go swooping among icebergs - even land on one - and then go up the cracked and jumbled face of the glacier, high over snowfields and a 3,000m mountain top, then back down, opening the door so there is nothing between us and Antarctica.
I'm just wondering if we'll still be around for dinner and another walk at Rothera when the ship's hooter sounds, summoning everyone back aboard for a hasty departure ahead of schedule.
A large iceberg has broken apart and fragments weighing many tonnes are drifting towards us. We escape intact and head on South.
THURSDAY 7 FEBRUARY - MEETING THE SCIENTISTS
I woke up to find HMS Endurance sailing to-and-fro across Ryder Bay, next to the UK's Rothera Research station, surveying the sea bed.
Not a chicken, but an American sheath-bill
After breakfast, one of the ship's boats is launched to carry a Navy team on a boat camp, surveying nearby islands. They will stay around Rothera tomorrow while we sail even further south.
Eventually, the neat buildings and airstrip of Rothera come into view. Standing on the Bridge listening to the commands, it seems like a delicate ballet as the vast ship literally inches into the wharf, avoiding an inconvenient iceberg nearby.
I've a lot to accomplish today, as several science teams have just returned to Rothera from "deep field" expeditions over the Antarctic summer into the heart of the continent. I want to catch them for interviews before they move on.
There's a tantalising delay as we tie up, before Rothera Station Commander Steve Hinde comes aboard to welcome us and brief us on the safety rules at this busy outpost.
A snow petrel accompanies HMS Endurance through open water
In the summer, about 120 scientists and support staff are based here. In the winter it's down to just 18 souls.
There's a good airstrip of fine, compacted gravel and a hangar for the British Antarctic Survey's Dash-7 and four Twin Otter aircraft.
They ferry in supplies and personnel from Chile and the Falklands, and take them on over the ice, often via the blue ice runway and re-fuelling post known as Sky Blu.
By the time presenter Gabrielle Walker and I get ashore, the British Antarctic Survey's wonderful press officer Athena Dinar has gone ahead of us and made contact with the key researchers we want to meet.
But before we do so, it's off to the other end of the station with all our communications gear to get a clear view to the satellite in the north.
It seems bizarre to be setting up what is essentially a mini studio on a beach in gentle snow, with the soft sound of small icebergs jostling in the ripples.
Captain Bob Tarrant prepares to go on her majesty's service
We get a good signal back to London and Gabrielle is interviewed by Five Live about the signs of climate change down here.
She's well-qualified to answer, having a passion for ice and being co-author (with Sir David King, who was until recently the UK's government chief scientific adviser) of The Hot Topic, a definitive guide to climate change.
The broadcast goes well, in spite of some challenging questions about the amount of carbon dioxide released by journalists visiting Antarctica.
We're ready for lunch and it's a joy to discover fresh, crisp salad and home-made bread in Rothera's dining room.
After lunch, there is a chance to meet the scientists who have just returned from the field.
Three are back from Lake Ellsworth, a lake buried under 3,000 metres of ice in the Western Antarctic interior, where they've been letting off small explosions to create seismic waves and measure the depth and shape of the lake.
A skua looks for an opportunity to grab an quick and easy meal
Another team has just returned from the Pine Island Glacier, a vast river of ice that seems to be accelerating, transporting ice with the potential to raise global sea levels.
I'll report on their science elsewhere, but it's exciting to meet people with such tales to tell.
Then we go down to visit Professor Lloyd Peck in the station's aquarium. He has been studying the marine invertebrates around Rothera.
You might think that the cold, harsh Antarctic environment would lead to marine creatures being stunted and small.
Not so; the low temperatures decrease metabolism so the cost of living is low. Cold water can also dissolve more oxygen and both factors mean that animals can grow large.
Lloyd likens it to moving to a cheap neighbourhood where you can afford a much bigger house. So there are sponges that a diver can climb into, starfish the size of a dinner plate, sea spiders bigger than your hand, and something like a marine woodlouse you wouldn't want to meet on a dark night - the monster in the film Alien is said to have been inspired by it!
Finally, we visit the communications tower for a routine short wave link-up with scientists working high up Mount Haddington on James Ross Island at the northern tip of the Antarctic Peninsula.
We'll be visiting them later in this trip to fly them and their 24 tonnes of equipment out.
They're drilling an ice core into a glacier in the hope that it will tell them about climate changes in the region over the last 10,000 years.
The good news is that they've drilled down 345 metres and are ahead of schedule.
Weather permitting, there's a plan to land a plane on the mountain the next day to bring some of the ice cores out.
The radio operator asks field assistant Sam if they need any "treats" (snacks and chocolate).
"No, we're fine for treats," she replies, "as long as we get the extra beer we've ordered, we'll be happy!"
WEDNESDAY 6 FEBRUARY - HELLO LONDON...
HMS Endurance awaits the return of its crew from Port Lockroy
It's time to test some of the technology we have brought with us. The key component is a small satellite-receiver that looks like a large laptop computer.
I set it up on one of the top deck decks of HMS Endurance, where we have a clear view to stern to the North.
When first switched on, the device finds its own position using GPS (Global Positioning System) satellite signals. Then I angle it on a tripod towards where I think the Inmarsat Atlantic West satellite must be, 36,000km above the equator.
From this latitude, it means pointing it almost horizontal and I make sure that no one can walk in front of it to receive a dose of microwaves and disconnect us in the process.
We joke that this far South, even a penguin walking in front of it might take us off the air. An audible beep rises in pitch with the signal strength as we lock on to the satellite.
Lockroy's population of breeding pairs of gentoos continues to grow
I find it amazing that, with lightweight equipment, I can get a broadband Internet connection on a moving ship crossing the Antarctic Circle.
Later in our expedition we will be using the link-up for studio quality connections to BBC radio programmes back in London. Today we are trying a different technology (a voice over Internet (VOI) provider) to record interviews.
The first is to my colleague Gareth Mitchell, who presents the World Service programme, Digital Planet. He is sitting in his home in London using his ordinary laptop computer and yet we can talk in reasonable quality and with remarkably little delay. We discuss digital communications to remote places.
The next call is in connection with a BBC supported project called School Report.
For this, hundreds of schools across the UK are putting together their own news programmes for radio, TV or online, with the pupils conducting interviews, selecting stories and editing and presenting the material. Our link-up is with Moorhead College in Lancashire.
A noisy helicopter interrupts a link-up with schoolchildren in the UK
Just as we start recording, a helicopter comes in to land on HMS Endurance, drowning out our voices but providing some exciting sound effects. When it has shut down, young girls at the school put a series of remarkably perceptive questions to my colleague and climate expert Gabrielle Walker.
We are as thrilled as they are to be able to speak so clearly over such distances.
After lunch it is announced that we have crossed the Antarctic Circle and that the channel between Adelaide Island and the Antarctic Peninsula is sufficiently free of ice for us to go the more direct and most picturesque route to Rothera, the UK's main research station in the region.
It is a magical journey among floating icebergs, some of them a rich blue colour indicating ancient ice with few bubbles. The ice may have formed far inland millions of years ago, to be carried inexorably to the sea in glaciers.
The speed of those glaciers is a crucial factor affecting sea level around the world. If they accelerate as the region warms, it could be bad news for Pacific atolls and low-lying regions as distant as Bangladesh or even London.
TUESDAY 5 FEBRUARY - LIFE ON THE OCEAN WAVE
The first of two very welcome days at sea as we continue south towards the British Antarctic Survey's Rothera Research Station.
But the days are not empty nor boring, nor is our course direct.
HMS Endurance is sailing to and fro in an area known as the Grandidier Channel.
The crew is surveying the sea floor with a sonar technique known as swath bathymetry, which can map the sea floor not only directly beneath the ship but in a wide swath to the sides as well. Much of this area has never been charted in detail before.
Although we are not going ashore ourselves, it is still a busy day and the dreaded wake-up whistle, piped to loudspeakers in every cabin, comes an hour early at 0600.
Members of the ship's company embark by helicopter to set up geodesic survey points on nearby islands.
In some cases the old charts are very inaccurate; at one point, while I am on the Bridge, the Officer of the Watch announces that, according to the charts, we are sailing across dry land.
Fortunately, the old charts are inaccurate and we are still in 150 metres depth of water!
The helicopters are busy today. A small group is visiting Vernadsky base, formerly Britain's Faraday base but now operated by Ukraine. They still use one of the original instruments that first spotted the hole in the ozone layer.
A life-saving look that is unlikely to feature on Europe's catwalks
The captain is also off on a diplomatic visit, to the US Palmer Station, looking very dapper in his flight suit.
Life on an Antarctic research ship is a mixture of frantic activity and long waits.
The ship's officers are trying to integrate so many different activities among the naval personnel, the survey teams and the research scientists, not to mention their BBC media guests, that it is hard to please all the people all the time.
This is particularly true given the unpredictability of the weather and the occasional need for mechanical repairs. They do a brilliant job and life is never dull.
Just when you think you might have some free time, another activity intervenes.
Today, it's time to brush up on the safety training we received several months ago in Derbyshire. We go down to the Forward Hold where Mark Gorin, one of the British Antarctic Survey's polar guides, has set up ropes down the side of stacked cargo containers.
These field assistants are the unsung heroes of Antarctic research. Tough and experienced in polar survival and mountaineering, they go ashore with every team, ensuring that they have all the right clothing, safety equipment and emergency supplies.
These are the people who lead the way if we have to rope up to cross crevassed glaciers. They are also the people who would fall first into any crevasse they had not spotted and these are also the people who train us to get them out if such an event should happen.
We practice the knots to rope up and learn how to anchor ourselves first with an ice axe and then with snow stakes, should the person ahead of us suddenly disappear into the ground.
We are trained how to abseil down into the crevasse to help an injured colleague, how to climb back out again on ropes using jumas to clamp to the ropes, and we learn how to set up a system of pulleys to haul an injured or unconscious person from the crevasse.
As we continue to sail south, hoping to reach further than HMS Endurance has ever gone before, we are issued with yet more layers of insulating clothing, feeling more and more like spherical penguins in our movements.
Chinstrap penguins were curious about the visitors to the island
After lunch I am summoned to the Bridge. Captain Bob Tarrant sits me down on the stool next to his own high seat. I wonder for a few seconds what I have done wrong, and if I'm going to be disciplined.
But the twinkle in his eye gives the Captain away and he tells me to put my hands on the controls. I am now driving the ship.
The Officer of the Watch calls out instructions; I repeat them and apply the settings to the tiller controls.
It takes a little while to get used to the time lag between changing the controls and the ship responding, and to adjusting for the sideways wind pressure on the vessel, but Endurance is remarkably responsive and I manage to hold a course that doesn't zig-zag too much.
Now, we are crossing Crystal Sound, a magical landscape of still, cold water, distant snow-capped peaks and numerous icebergs.
Humpback and minke whales breach and dive in the distance, and many of the lower icebergs carry Weddell or crab-eater seals, lounging in the snow like giant slugs.
Snow petrels glide around the ship. One catches something from the still water. Immediately a skua appears from nowhere and swoops in, trying to steal the catch.
The petrel passes close to a Weddell seal on an iceberg; which raises its head. The skua veers off and the petrel gets its meal.
MONDAY 4 FEBRUARY - THE SCENT OF PENGUINS
It's a murky morning as HMS Endurance sails slowly among the islands towards Port Lockroy.
Icebergs loom through the mist and there's light snow in the air. Port Lockroy is a rather grand name for a small rock with a couple of huts on it, but it's one of the most visited places in Antarctica.
About 17,000 people came here last year with an average of two cruise ships per day. Built in 1944 as part of a secret British operation to monitor German activity in Antarctic waters, it later became a British Antarctic Survey research station.
It is now run by the UK Antarctic Heritage Trust which monitors the local penguins, run a museum and souvenir shop and stamp visitors' passports.
After breakfast on board, we form a chain to pass 60-something boxes of supplies from the hold to the Quarterdeck, where they're loaded into Endurance's two rigid inflatable boats and taken ashore.
The penguins were enjoying the surf
One of the boats comes back with Rachel Hazell, Port Lockroy's postmistress, penguin monitor and a former artist-in-residence for HMS Endurance.
She knows our ship has a facility for a hot bath and, with no running water on the island, is keen to make use of it.
Then there is a chance for many of the ship's company to go ashore. Unfortunately, in these freezing waters, that means another even more cumbersome rubber immersion suit, even for the short boat ride to Lockroy.
The first things my eyes notice on arrival are penguins - hundreds of them. There are, in fact, 600 breeding pairs of gentoo on the island, concentrated like loyal supporters around the Union Jack that flatters proudly from a pole in front of the main hut.
My nose notices the penguins too! It's not so much the birds, they bathe regularly in the cold, clear waters; it's what they leave behind.
Once I climb out of my immersion suit I'm very glad of the wellies manager Rick Atkinson has lent to me.
I ask him how he copes with the smell day-in day-out: "What's smell? After a day or two there is no detectable odour," he says.
The site of Port Lockroy was originally picked because it was free of penguins. They only began turning up in the 1970s. There's a new study looking to see if human visitors stress the penguins.
It seems to be quite the opposite; the flightless birds collect around the huts where their predators fear to go. However, there was one skua picking the eyes out of a dead penguin chick.
But 760 penguin chicks have been born there this year - the population of gentoo is expanding and spreading south. Perhaps this could be another consequence of a warming world?
There is another curious bird among the penguins. At first I thought Rick must be keeping small white chickens. They turn out to be American sheath-bills. I don't like to think what nutrition they may find in the penguin waste!
All too soon it's back to Endurance, but another treat awaits us. The clouds are lifting as we enter the Lemaire Channel - a narrow, fjord-like passage between towering rocky peaks and snowfields, littered with icebergs.
It's as if someone had taken the Alps, increased the snow and ice and half submerged them in the sea.
SUNDAY 3 FEBRUARY - 'SUB-ZERO SOIL SAMPLES'
Today, the port hole lets in brilliant sunshine across a calm sea littered with icebergs.
At the 0800 briefing, it's confirmed that we will get our second outing today, this time to Gant Island, between Anvers and Brabant Islands to the west of the Antarctic Peninsula.
We'll be travelling with soil scientists from Stirling University and the Scottish Crops Research Institute.
Somehow, the goon suit seems more bearable today, perhaps this is a result of familiarity, or perhaps it is the shorter wait for our helicopter after the other has gone out whale watching, fitted with a special camera from the BBC Natural History Unit.
Digging for dirt
We land in a beautiful spot on level snow next to a pebbly beach littered with moulted seal fur and whale bones.
On one side, a rocky headland, on the other a steep cliff with lots of soil-filled crevices - and a wonderful snow slope for sliding down on the seat of your waterproof trousers.
Researcher David Hopkins is already scrabbling away in the thin soil that has been washed down on to the snow from among the rocks.
Each of his small sample tubes of soil, he says, probably contains 10 million or more bacteria from thousands of species.
These bacteria are the heart and lungs of the ecosystem, albeit in the harsh conditions of this continent of faint heart and shallow breath.
Some samples he'll simply keep in the fridge to examine later, but others he plunges into a mixture of dry ice and alcohol at -80C (-112F), freezing the genes of the bacteria in order to reveal their activity at the time they were collected rather than after a journey around the world.
Across the little bay, less than 100 metres away, is the tip of a glacier. It's deeply crevassed and looks most unstable in the afternoon sun.
We've more time here than we had yesterday so as we eat our sandwiches, I set up a microphone on a rock and leave the recorder running.
Spert Island is several kilometres across
Ten minutes later it captures the rumble and crash as a block of ice the size of a large car crashes into the bay.
I turned to examine some rocks by the shore and glanced back to see a gentoo penguin just a few metres behind me. I could swear he wasn't there a minute ago.
He seems completely unconcerned as I clamber past to get my camera and only mildly interested when I return to snap him.
While we wait for the helicopter, goon seats in the snow, a little troupe of chin strap penguins head towards us through the water and hop out to pose for photos in the sunshine. This must be Antarctic at its best.
The pilot does not have to apologise for keeping us waiting, but as a treat on the way back he takes a small detour around a family of humpback whales, circling in the crystal waters and waving with their great fins and tails.
SATURDAY 2 FEBRUARY - 'GOON SUITS'
When I looked out of my porthole at 0700 this morning, I could see the first hint of a distant snow-capped peak. This came after a restless night subjected to random G-forces as we pitched and rolled between 5m-high waves. But this is still not Antarctica.
We're passing the western end of the South Shetland Isles, a chain that runs east to Elephant Island where Shackleton overwintered in 1916.
The "goon suits" allow only a limited range of movement
But the Antarctic Peninsula is getting ever nearer, the sea ever calmer and the sky ever clearer. The plan is, when we get within flying range of some of the little-explored islands close to the continent, to get a helicopter out and drop a party of scientists ashore to collect samples. And I get to go with them.
I've been conditioned by the "helidunk" course to think that each time I get into a helicopter it will crash into the sea, so it comes as no surprise when I'm told to put on about five layers of warm clothing and then climb - boots and all - into a whole body rubber immersion suit.
They are known locally as "goon suits", and certainly leave me feeling like a "goon", with a similar range of movements to a stranded penguin. Add to that a helmet with earphones and goggles, place a radio microphone in the earpiece to record in-flight communications and I'm left almost unable to move, looking very silly in my personal rubber sauna bath.
We wait, gently steaming, until, suddenly, our flight is called and we are whisked into the hangar.
Things happen with military precision here. Everyone knows their own role, be it refuelling the choppers or checking we have zipped our suits up correctly. Then they take us forward onto the helideck, almost by the scruff of the neck, and guide us under the spinning rotors to our seats.
Once pilot, observer and safety packs of camping gear are on board, there is only room for three passengers on the Lynx helicopter. So the first science team has gone ahead on a previous flight to find a landing site and begin sampling before we come and distract them.
A humpback whale breaching was one of the highlights of the trip
On the map, Trinity Island looks tiny, dwarfed by the mountains of the Peninsula. A good place to land perhaps? In reality it turns out to have sheer cliffs of rock and ice, with no obvious landing site.
So the scientists have opted for the interestingly named Spert Island nearby - scarcely a dot on the map, but still probably several kilometres across. We touch down on a flattish cliff top, covered in lichen-encrusted rocks.
We've very little time and the helicopter will wait with us. But there is just time to climb out of the rubber suits and breathe again! Then it's off on safari with British Antarctic Survey (Bas) scientist Pete Convey to see the biggest land animals on the continent.
Martin basks in the majesty of Overton Peak
Everyone thinks of marine creatures when considering Antarctica - whales, seals and penguins, or the skuas screaming at us from the air. But there are land creatures too.
They are springtails; plant-eating arthropods a millimetre or so long. Then there are the carnivores - the lions of this Antarctic micro jungle.
They're mites smaller than a full stop. Pete Convey is collecting them for identification to see how far south they range. There must be some point where it simply gets too cold for them to survive, even with their biological antifreeze.
Will we find that transition and could it be moving south as the Peninsula warms? All the climate models show this area as the hottest hotspot for warming on the planet with perhaps a 5C rise still to come this century.
The other little creature Pete Convey is searching out is the larvae of a tiny wingless midge. He freezes some of these to take home for genetic analysis. Comparisons with related species elsewhere in the world suggest that these Antarctic flies have survived in isolation on the continent for perhaps 45 million years.
All too soon it is time to don goon suits again and get back in the helicopter. Pilot Colin plays a little joke on us as we take off and pretends to let the craft fall off the edge of the cliff towards the icebergs.
But thankfully ditching at sea is not the norm that it seemed on the helidunk course and we're soon back on HMS Endurance for something rare in Antarctic exploration - a hot shower, good food and a cosy bed.
FRIDAY 1 FEBRUARY - DUE SOUTH
At last we're heading South.
I'm on board the Royal Navy icebreaker HMS Endurance, along with her crew and a team of scientists from the British Antarctic Survey.
With presenter and ice-enthusiast Gabrielle Walker we'll be making programmes for BBC World Service about one of the hottest topics of our age - climate change - in the region that's experiencing perhaps more change than anywhere else on the planet - the Antarctic Peninsula.
Our trip has been months in the planning. Endurance is equipped with two Lynx helicopters that will enable the scientists - and, I hope, us - to reach places that would otherwise be inaccessible, though the weather can still change plans hour by hour.
While the researchers prioritise their objectives, we have all been having intensive safety training.
Prepare for the worst
Antarctica can be an unforgiving continent. In spite of the fears about global warming, temperatures can plunge far below zero degrees and survival time in the sea without an immersion suit is measured in minutes.
The nearest hospital is likely to be several days away, so the emphasis is always on prevention - but also on preparedness should the worst happen.
Along with medicals and dental checks, we've had a full first aid course and a fieldwork course in Derbyshire, camping in the Pennine hills. Here we learnt ropework and abseiling and how to rescue each other from a crevasse. With a little imagination, we could conjure Antarctic snow and ice from the rain and millstone grit of the English Midlands.
But most feared and spectacular was the infamous "helidunk course". It takes place in a deep swimming pool at the Fleet Air Arm base in Wiltshire. Basically, you climb into a mock-up of a helicopter which is then dropped into the pools and sinks, upside down, in pitch darkness.
You just have to get out alive through the windows. Actually, it's not as bad as it sounds. They don't simulate Antarctic temperatures, you get to practice in full light first, there are divers on hand if you get stuck, and no one spends more than about 15 seconds underwater. And since I hate opening my eyes underwater, the one in darkness was no worse than the others.
So here we are, as fully trained as I'm ever likely to be, sailing South from the Falklands, accompanied by storm petrels, black-browed albatross and the occasional dolphin, across the notorious Drake Passage, capable of producing the roughest seas on the planet.
Today, there's what a seasoned sailor would call "a reasonable swell" - waves of a few metres breaking over the bows. I love to watch them, though they have sent some scurrying, pale-faced, for bucket, bunk and pill.
After several days of running around, headless chicken-like, in the knowledge that those batteries, wires and waterproofs I forget to pack will certainly not be obtainable from a store down the road, here we are in a sort of limbo, getting to know the crew and waiting for the first iceberg on the southern horizon.