doi.org/10.22498/pages.horiz.1.12
n Sea: se d n u m A e th f o s th p e d e From th mate! li c re tu fu f o ts in h h it w re Hidden treasu Margot Courtillat and all the scientists from IODP Expedition 379 The news isn't great! You may have already heard: the
The IPCC also highlighted that the marine ice sheet
climate is changing, and sea level is rising. But did you
from the Amundsen Sea Embayment, the indentation
know that the East and West Antarctic Ice Sheets, giant
in the shoreline which forms an open bay, will likely
masses of ice covering the continental land, could be
be one of the major contributors in the substantial
one of the main reasons for this?
increase in sea-level rise over the next century. The Amundsen Sea is located right in front of the West
In 2018, the Intergovernmental Panel on Climate
Antarctic Ice Sheet and to the south of the Pacific
Change (IPCC) Special Report on Global Warming
Ocean. The West Antarctic Ice Sheet is suspected to
concluded that the instability of the marine ice sheet in
have previously collapsed 3–4 million years ago, when
Antarctica and the irreversible loss of the Greenland Ice
temperatures were like today. One such collapse raised
Sheet could be triggered by a rise of about 1.5 to 2°C
global sea level by several meters. But to be sure of this
(34.7 to 35.6°F) in the global temperature. This could
we needed to have more information about its behav-
then lead to a rise of the ocean of several meters, over
ior over the last few millions of years. This is the main
hundreds to thousands of years.
reason why the International Ocean Discovery Program (IODP) decided to organize Expedition 379 to drill the marine sediments from the Amundsen Sea.
Marine sediments You are now probably wondering why we need to drill marine sediments to know the history of an ice continent, and that is a good question! When an ice sheet retreats, a lot of icebergs are released. Together with the ice itself, they also transport dirt (also known as sediment) into the sea. This sediment, which eroded from the continent, falls onto the seafloor when the iceberg melts. It falls in chronological order: that is, old sediments end up on the bottom and young ones at the top.
Antarc tica and Figure 1: Map of seas (NASA). its surrounding 12 PAGES HORIZONS • VOLUME 1 • 2021
