{"id":2666,"date":"2021-12-17T10:03:31","date_gmt":"2021-12-17T10:03:31","guid":{"rendered":"https:\/\/thepoetryofscience.peachpuff-wolverine-566518.hostingersite.com\/?p=2666"},"modified":"2021-12-17T10:03:31","modified_gmt":"2021-12-17T10:03:31","slug":"close-as-a-clam","status":"publish","type":"post","link":"https:\/\/scienceblog.com\/thepoetryofscience\/2666\/close-as-a-clam\/","title":{"rendered":"Close as a Clam"},"content":{"rendered":"

We scavenge the coastlines,
\nin search of
\nliving, low-tech tools
\nthat carry within them
\nthe promise of
\nour climate\u2019s past
\nand future tense.<\/p>\n

Geochemical proxies
\nthat peer into the depths,
\nthe highs
\nand lows
\nof every season
\netched into the calcite,
\nlying in wait
\nto be read
\nlike withered,
\nbriny runes.<\/p>\n

Drilling each edge
\nwe scry secrets
\nfrom shells,
\nthe rising tides
\nand
\nfalling heat
\nunfurl in unison
\nbeneath the surface
\nof our touch.<\/p>\n

\"\"<\/a>
An example of the Donax obesulus<\/em> surf clam that was used in this study to observe historical ENSOE events (Image Credit: Conchology).<\/figcaption><\/figure>\n

This poem is inspired by recent research<\/a>, which has found that Earth\u2019s past climate is recorded in clam shells.<\/p>\n

The El Ni\u00f1o-Southern Oscillation (ENSO) is a recurring climate pattern which involves changes in the temperature of waters in the central and eastern tropical Pacific Ocean. ENSO is one of the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation, which in turn, influences temperature and precipitation across the globe. As such it is vital to try and measure historical sea surface temperatures so that we can better understand how ENSO behaved in the past, and in turn help us to predict how it will behave in the future. Historical ENSO patterns can be observed by using long proxy records, such as annually resolved tree-rings, coral, ice-cores, and even clams.<\/p>\n

Like trees and tree rings, clams create layers in their shells as they grow, with the chemical composition of each layer depending on the sea surface temperature at the time. By drilling along a clam shell it is possible to collect samples at each interval of time during its lifespan, thus giving a snapshot of the ocean temperature as the shell grew, at yearly, monthly, and even weekly intervals. In this new study, researchers collected samples of the Donax obesuluscan clam species from fish markets and coastal beaches near the Nepe\u00f1a Valley in Peru in 2012, 2014, and 2016. By comparing the relationship between the chemistry of the shell and records of the ocean temperature from these time periods, the researchers found that these clams record sea surface temperature pretty accurately. Given that many ancient civilizations consumed such clams and left their shells at archaeological sites, this research thereby presents a novel way to reconstruct the climate and its fluctuations from the distant past.<\/p>\n