Booth Island, Antarctica (2007) — Diners of shrimp-like, red krill, gentoo penguins with down-coated chicks nest on the freezing rocks off the coast of the Antarctic Peninsula. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — A juvenile emperor penguin, the largest species of penguin, is far from its distant home way to the south. But on a small ice floe, north of the Antarctic Peninsula, it has found a friendly pair of chinstrap penguins. Not long after the ship encountered them, all three penguins dropped to their bellies, slid into the water, and swam off together. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — Northeast of the Antarctic Peninsula, straddling the boundary between the Scotia Sea and the Weddell Sea, the surface seems to be covered more by ice than by open water. The giant, flat-topped, tabular icebergs have broken off of Antarctica. They can be more than a mile long and taller than ships, which doesn’t take into account that about 90% of their mass hides below the waterline. They can be tracked from space. Ice that forms on land and enters the water will raise the sea level when it melts. However, pack ice (in the foreground to the right), which forms when the seawater freezes, is not more than a few feet tall and doesn’t add to the sea level when it melts. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — Radar mounted on the mast tracks the icebergs. On the radar screen, the ship is at the white cross. The green dots are icebergs. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — Back in the day, a selfie stick was me sticking over the bow of the ship and hanging over as much as possible. One hand on the railing and one eye watching for something that might rock the boat. Here’s the hull above and below the waterline. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — Sailing through the pack ice can be slow going, especially when having to weave around icebergs. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — Here’s the bow moments before the ship rams into an iceberg. With an ice-strengthened hull, the ship can cut through small patches of pack ice. But eventually the ice can be too much. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — Not sure how much good this life preserver would be. The water is subzero (salt water has a lower freezing point than freshwater). (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — When you hear “chart a course,” this is what it looks like. Sailing west from the South Orkneys toward the Erebus and Terror Gulf, the ice became too hazardous for passage. Instead of heading to Paulet Island, as this navigation chart shows, the ship had to detour north, circle around the islands, and come east through the Antarctic Sound. (Photo by Dan Linehan)

Lemaire Channel to Petermann Island, Antarctica (2007) — Crabeater seals, like this pair, prefer to haul themselves out on icebergs, in contrast to Weddell seals, which can often be seen onshore. Contrary to what their name would indicate, crabeaters prey mainly upon krill; crabs are not high up on their menu. (Photo by Dan Linehan)

Ushuaia, Argentina (2006) — This crabeater skull at the Museo del Fin del Mundo shows how uniquely adapted the crabeater is to eating krill. Not only do the teeth have spiky tines, but the upper and lower teeth are spaced in such a way that allows them to tightly fit together while the jaw is closed. So, when a crabeater snatches a mouthful of krill, it can strain the water out before swallowing the krill trapped by its teeth. (Photo by Dan Linehan)

Southern Ocean to Antarctica (2007) — The seas around Antarctica are filled with icebergs of all shapes and sizes. Uneven melting, fracturing apart, and tumbling over due to top-heaviness are actions that all help to dramatically change the forms of icebergs. (Photo by Dan Linehan)

Paulet Island, Antarctica (2007) — Adélie penguins wisely keep an escape route to the water open and a safe distance away from a leopard seal snoozing on an iceberg off the coast. Aside from fish, penguins are common prey for leopard seals. Leopard seals only inchworm along the ice, but in the water they are powerful and agile enough swimmers to catch penguins. In turn, killer whales hunt seals. Even those resting on icebergs are not necessarily safe. Using teamwork, killer whales can tip over small icebergs or thrust waves upon them so that seals fall off where other killer whales are waiting. (Photo by Dan Linehan)

Antarctic Sound to Paulet Island, Antarctica (2007) — Three Adélies porpoise near Paulet Island, which has a large Adélie colony. As these penguins go airborne to catch a breath, they can also survey the land around them. (Photo by Dan Linehan)

Paulet Island, Antarctica (2007) — Related to cormorants, these Antarctic shags feed by plunge diving into the water to swim after fish. Later, after preening each other, their beaks are covered with small pieces of feathers. (Photo by Dan Linehan)

Paulet Island, Antarctica (2007) — This hauled-out Weddell seal is one of four types of seals typically found around the Antarctic Peninsula. Similar looking to a crabeater seal, the Weddell is slightly larger, plumper, and often seemingly no-necked. The shape of leopard seals and the size of elephant seals make them easily distinguishable from Weddells. (Photo by Dan Linehan)

Paulet Island, Antarctica (2007) — In Antarctica it is too cold and desolate and extreme for organic matter with any kind of nutritional value to go to waste. The snowy sheathbill, with a featherless, vulturelike face, will feast on mostly anything, including shed skin and dung from seals. (Photo by Dan Linehan)

Paulet Island, Antarctica (2007) — This Adélie scored big-time. How did it first woo its mate below? Possibly a pickup line like: “Why don’t we waddle back to my stone nest? It’s the biggest on the island.” There is no worry about another penguin stealing these rocks. They were put here by marooned explorers. A nearby plaque reads: “Larsen Stone Hut from 1903: On the Swedish Antarctic expedition of 1901–1903, Otto Nordenskjöld and his 5 colleagues established a scientific wintering quarter at Snow Hill Island. On return to call for the wintering group at Snow Hill, the Expedition ship Antarctic, mastered by Norwegian pioneer Caption C. A. Larsen, became victim of pack ice in the Weddell Sea, was abandoned, and sank on February 12, 1903 at 12:45 hours. After 16 days of dragging boats over moving ice, they reached Paulet Island, and this stone hut was completed on March 7th by the group of twenty men.” The explorers were rescued from Paulet on November 10, 1903 by the Argentine ship Uruguay. In the background of this photo, a Zodiac races by an iceberg. (Photo by Dan Linehan)

Paulet Island, Antarctica (2007) — Trailing a plume of froth, an Adélie rockets out of the water to the top of an iceberg several feet high. Other penguins on the iceberg step closer to the edge and prepare to dive in. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — At Baily Head, the easternmost point of the island, one of the largest chinstrap penguin colonies in Antarctica can be found. A rivulet of glacier meltwater forms the easily crossable divider of a penguin highway. By looking at the feather colors, it is easy to see which direction the penguins are traveling, returning to the sea on the right and returning to the colony on the left. At least for the most part, they drive on the correct side of the road. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — Perched on a cliffside and at a distance away that requires a telephoto lens to see it clearly, this skua keeps a sharp eye on the creatures moving about. Getting too close to its chick will provoke an attack. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — A threatening snowstorm forced an early departure from the outer rim of Deception Island. The blackened landing beach to the right and Sewing-Machine Needles to the left straddle Baily Head. Behind these formations toward the land in the distant background is Neptune’s Bellows, which opens up the interior waters of Deception Island. Obscured by the clouds at first, the Adele emerged like a sleek iceberg or ghost ship from the past. But the story changed when it got closer and easier to see. Launched in 2005, the superyacht has a 180-foot-long aluminum hull, and its tallest mast reaches above 200 feet. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — The bright green on the radar screen highlights the land inside Deception Island that encircles Whalers Bay. The land at the bottom of the screen is Cathedral Crags, which is one end of Neptune’s Bellows. A little ways off the radar screen, in the direction of about 165°, is Ravn Rock, a submerged rock in the middle of the entrance into Deception Island’s caldera. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — Many countries have had bases inside the caldera. This structure was buried by mud resulting from volcanic activity. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — One of the uses of the island was for whaling. This boat in front of Neptune’s Window was itself a victim of an inescapable force. (Photo by Dan Linehan)

Deception Island, Antarctica (2007) — Steam rises from the shore where we will soon land. Many eruptions over the decades have destroyed bases built here. After all, the island is the tip of a giant, active volcano. Apparently, being such a safe harbor, and an airfield at one time, has been worth the risk. (Photo by Dan Linehan)

DVD Chapter / Paulet Island, Antarctica (2007) — Though the island is an inactive volcano, the traces of volcanism are easily seen by simply looking down by your feet where the snow is melting. These red and black, lightweight rocks called scoria formed from magma trapping tiny pockets of gases as it solidified. (Photo by Dan Linehan)

Cuverville Island, Antarctica (2007) — Sometimes what is not in a photograph is just as important as what is in a photograph. What you see here is a penguin family. The mom is sitting with the chicks as dad grabs rocks to build up their nest. What a fine, upstanding household, right? What is not shown is that dad steals his rocks from other penguin nests. Before you judge this guy, know that this colony, much like many others, has a thriving rock black market. If I expanded this photograph out on the right-hand side, you’d likely see a penguin grabbing a rock from this very nest. A penguin will even walk right by perfectly good rocks scattered on the ground on its way to abscond with one swiped from a neighbor. Forget about flowers. Nothing says “I love you” to a penguin mate more than a warm rock. (Photo by Dan Linehan)

Cuverville Island, Antarctica (2007) — Looking nothing like elephant, Weddell, or crabeater seals, this muscular leopard seal seems almost reptilian. Seeing this creature up close from a Zodiac helps to understand how sea monster legends might start. (Photo by Dan Linehan)

Cuverville Island, Antarctica (2007) — Preferring to nest on rocky ground, gentoo penguins choose to colonize Cuverville Island. This might not seem too cozy, but the island offers the penguins much easier access to the water—free from fast flowing and falling ice—compared to the glacier-covered Antarctic Peninsula across the way. The Whale Song steams by, a 92-foot-long research vessel specially designed for quiet operation and used by Australia’s Centre of Whale Research to study whale songs and vocals. (Photo by Dan Linehan)

Lemaire Channel to Neko Harbour, Antarctica (2007) — Stacked alongside the channel, these twin peaks are officially but less commonly known as the Cape Renard Towers. Made of basalt, a volcanic rock formed by the firming of oozing lava, the pair of snowcapped buttresses is more affectionately referred to as Una’s Tits by locals and passersby. (Photo by Dan Linehan)

Wiencke Island, Antarctica (2007) — Whale bones penetrate the blue like an ice-capped mountain peak. And their whiteness stands out from the rocky terrain like glacier ice or the belly feathers of penguins. (Photo by Dan Linehan)

Wiencke Island, Antarctica (2007) — These two skulls belong to blue whales, the largest animals ever to live on our planet. From the many bones ashore, a mostly complete blue whale skeleton was assembled on the iceless ground. (Photo by Dan Linehan)

Wiencke Island, Antarctica (2007) — In Antarctica, almost everything is exposed. There are no trees. On a day when the temperature skyrockets well above normal, finding refuge is almost never an option. But these lucky penguin chicks have discovered a way to cool off by taking shelter in the shadows of bones. (Photo by Dan Linehan)

Wiencke Island, Antarctica (2007) — When it gets too hot in Antarctica, it is easy for people to take off their jackets. However, penguin chicks have it rough when it gets hot. They have blubber and a heavy, non-removable coat of down feathers adapted for cold weather survival. Chicks cannot even take cool, refreshing dips in the water because their down feathers are not waterproof, and they would end up drowning. At Jougla Point, this overheated gentoo chick, with its tongue out, is panting. (Photo by Dan Linehan)

Wiencke Island, Antarctica (2007) — A quick look inside this seal’s mouth reveals that it is not a crabeater. The Weddell seal here has teeth with shapes more similar to those found in many other seal species. (Photo by Dan Linehan)

Goudier Island, Antarctica (2007) — A secret British mission established Port Lockroy in 1944. It was the first permanent British base in Antarctica. After World War II, the operations focused around scientific endeavors, leading to the formation of the British Antarctic Survey. The base closed in 1962 but was named a Historic Site and Monument. In 1996, Port Lockroy was restored as a museum with a functioning post office. (Photo by Dan Linehan)

Goudier Island, Antarctica (2007) — “Beastie,” otherwise known as the Mark II Union Radio Automatic Ionosonde, was used at Port Lockroy between 1953 and 1961 to study radio communications and the atmosphere. The long-term ionosphere data it obtained by transmitting radio pulses into the atmosphere and measuring their echoes led to a better understanding of the atmosphere above Antarctica and beyond. (Photo by Dan Linehan)

Anvers Island, Antarctica (2007) — Palmer Station is one of three US scientific research stations in Antarctica and the only one on the Antarctic Peninsula. McMurdo Station near the Ross Sea and the Amundsen-Scott South Pole Station are the other two. For decades these bases have conducted wide-ranging studies that cover all the major disciplines of science. (Photo by Dan Linehan)

Anvers Island, Antarctica (2007) — Usually swimming in the open ocean, this crustacean in a research tank at Palmer Station is called an Antarctic krill. It can grow up to a little more than 2 inches in length. Out of all multicellular organisms, krill are said to comprise the most biomass on the planet. They are indeed an important fuel of the world’s ocean ecosystems. The largest animals in the world—blue whales—feed on krill. So do other whales, seals, fish, birds, and many other animals. Many species of krill depend on sea ice to grow. As sea ice habitat disappears, so to the numbers of krill. This affects all animals connected to its food web. (Photo by Dan Linehan)

Petermann Island, Antarctica (2007) — Though the island is slightly above the Antarctic Circle (66° 33’ 39” south latitude) and quite a ways from the South Pole, the Sun dipped below mountains on the Antarctic Peninsula to the south and didn’t seem to move much more. Sunset was 10:54 pm, but the sky was still lit while we were returning to the ship just before midnight. The Sun didn’t stay down for long. Sunrise followed at 3:42 am. (Photo by Dan Linehan)

DVD Chapter / Cuverville Island, Antarctica (2007) — Under normal conditions, ice melts at exactly 32°F (0°C). Around this temperature, mere fractions of a degree do make a difference in whether ice will melt or not. The higher the air temperature surrounding this iceberg floating near Cuverville, the faster it will melt. (Photo by Dan Linehan)

Neko Harbour, Antarctica (2007) — Without a shirt on—because it was that hot—my expedition leader ascends a glacier-covered mountain to reach a lookout point for viewing Neko Harbour in Antarctica. (Photo by Dan Linehan)

Cuverville Island, Antarctica (2007) — Standing like reflections in a mirror, these two skuas have positions that beg questions. Does the heart they form between them symbolize that they are mates? Or is it the hourglass counting down the plan they’ve hatched? Perhaps both—a dinner date at the local penguin colony. (Photo by Dan Linehan)

Neko Harbour, Antarctica (2007) — On the north edge of the harbor, this glacier makes nearby Zodiacs look like specks on the water. Crevasses are a telltale sign that the glacier is moving rapidly. These wide, deep cracks occur as the ice splits apart from stresses that result from the glacier moving over the underlying land. It is like holding an icicle at both ends and slowly bending it until it snaps. (Photo by Dan Linehan)

Bransfield Strait to Livingston Island, Antarctica (2007) — The narrow opening of Neptune’s Bellows provides ships access inside the protective walls of Deception Island. To the right, the large, U-shaped notch in the rock is Neptune’s Window. One of the largest volcanic calderas on the planet, the island provides a haven to ships from rough seas and strong wings. But there is a price. Deception is still an active volcano, and it is guarded by Ravn Rock, a giant, submerged rock in the middle of Neptune’s Bellows. (Photo by Dan Linehan)

DVD Chapter / Buenos Aires, Argentina (2013) — All that remains for the picture from El Sanjuanino is a last empanada, this one filled with ham and cheese. The Malbec wine inside the traditional Argentine pitcher called a pingüino, which is Spanish for penguin, is almost gone, too. (Photo by Dan Linehan)

Gerlache Strait to Cuverville Island, Antarctica (2007) — Rampant whaling decimated the waters of Antarctica and the surrounding regions. Whales, like this humpback (BTBEL-Mn_02_158), still have not recovered. Some countries, with dubious rationales, continue to hunt whales in Antarctica. I’ve seen many more whales on single whale watching trips, lasting only a few hours, off the coast of Monterey, California, than compared to my combined time of nearly a month at sea in these pillaged waters. (Photo by Dan Linehan)

Happywhale is a wonderful website that helps people to identify the individual whales that they have observed. Once a whale in a photo is identified, people can see other photos of it and track where it has traveled. For more about this humpback whale (BTBEL-Mn_02_158), visit Happywhale here: Track This Whale

Bransfield Strait to Cierva Cove, Antarctica (2007) — A flock of cape petrels, or pintados, which means painted, races by the ship. With nothing but open water in every direction, these beautiful, vibrant seabirds remind us that we are not all alone. And just like that, they are gone. (Photo by Dan Linehan)