Eastern tropical Pacific hydrologic changes during the past 27,000 years from D/H ratios in alkenones
Further evaluation of long-chain alkenones
as indicators of paleoceanographic conditions.
To reconstruct the salinity, the WHOI team analyzed sediments containing highly resistant organic compounds called alkenones
, which are uniquely produced by Emiliania huxleyi-the same photosynthetic organism oceanographers study to determine past sea surface temperatures.
Researchers analysed marine sediment collected by drilling and measured alkenones
- organic compounds produced by phytoplankton.
Many papers discus the controlling mechanisms that may have forced major climate change, such as geographical and oceanographic changes during the Late Ordovician or changing ocean gateways in the Cenozoic, while others discuss biological and chemical proxies that can be used to track ancient climate change, such as the use of Ca/Mg ratio of foraminifer tests or alkenones
from surface- dwelling marine-algae.
A 5 million year comparison of Mg/Ca and alkenone