National Geographic - USA (2021-11)

me colonies
stable, and
e declining
sula,” says
ony Brook
in penguin
rctica—the
ns that the
really tells
out the way
at, no pun
g.”
e Antarctic
ming places
ring a heat
ord 64.94°F

at Argentina’s Esperanza Base, toward the north-

ern tip of the peninsula. (Summer temperatures

normally aren’t more than a few degrees above

freezing.) As air temperature rises, sea ice

around the peninsula recedes, and in 2016 it

dwindled to its least amount since satellite mon-

itoring of changes in the ice began in the 1970s.

That’s a problem, because freezing sea -

water shelters pinkie-finger–size crustaceans—

Antarctic krill—that are the key to the web of

life in the Southern Ocean. Teeming shoals of

A Weddell seal rests

in an iceberg meltwater

pool. One of the Ant-

arctic’s top predators,

the seals hunt for fish

and octopuses under

sea ice, emitting sounds

that may act as echo-

location to find prey in

dark water.

TOP: Wind, sun, and

snow combine to

create the intricate

shapes of Antarc-

tica’s icebergs. Air

bubbles trapped in

the ice as it forms

are released when it

melts, adding to the

sculpted contours.

BOTTOM: The icy

seascape is highly

dynamic. “We

watched one of

these arches

collapse,” says

photographer and

National Geo-

graphic Explorer

Thomas Peschak.

TOP (OPPOSITE):

Icebergs, such as

this rhomboid

one topped with a

turquoise meltwater

pool, rise at least

16 feet above the

water. As icebergs

shrink, they become

bergy bits.

BOTTOM (OPPOSITE):

The shifting ele-

ments transform the

Southern Ocean’s

icebergs into

ephemeral pieces

of art. “None of

them are the same,”

Peschak says. “They

always change.”

AN ICY WORLD IN MELTDOWN 107