The past lies buried under the sea

Kate Pound
Kate studies 3,000-year-old volcanic rocks in Iceland.
Photo credit: Kate Pound

For millions of years, glaciers have scraped rocks and dirt off of Antarctica and dropping them near the shore. Further out to sea, diatoms—tiny one-celled creatures with delicate shells—live and die, their bodies piling up on the ocean floor.

Kate and colleagues will drill for samples of sea floor material millions of years old. Layers of rock will tell them when glaciers were active. Layers of diatoms will indicate times when the sea was ice-free.

Diatoms hold special meaning. Some species require specific temperatures, salinity, nutrients, etc. The presence of such fossils will reveal environmental conditions at various points in the past.