![]() |
||
![]() |
![]() |
|
![]() |
![]() |
![]()
December
21, 2006 A few years ago, an
international
team of researchers went to the middle of the The researchers'
drilling
produced pristine samples of marine microfossils, otherwise known as
foraminifera. Analysis of the carbonate shells of these microfossils,
which are
between 23 million to 34 million years-old, has revealed that the
Earth's
climate and the formation and recession of glaciation events in the
Earth's
history have corresponded with variations in the earth's natural
orbital
patterns and carbon cycles. The researchers were
particularly
interested in these microfossils because they came from the Oligocene
epoch, a
time in Earth's history known for falling temperatures. "The continuity and
length
of the data series we gathered and analyzed allowed for unprecedented
insights
into the complex interactions between external climate forcing, the
global
carbon cycle and ice sheet oscillations," said Dr. Jens Herrle,
co-author
of the paper and a micropaleontology professor at the The authors also
show how simple
models of the global carbon cycle, coupled to orbital controls of
global
temperature and biological activity, are able to reproduce the
important
changes observed after the world entered an "ice-house" state about
34 million years ago. In the early half of
the 20th
century, Serbian physicist Milutin Milankovitch first proposed that
cyclical
variations in the Earth-Sun geometry can alter the Earth's climate and
these
changes can be discovered in the Earth's geological archives, which is
exactly
what this research team, consisting of members from the "This research is
not only
concerned with the climate many millions-of-years-ago. Researching and
understanding
'extreme' climate events from the geological past allows us to better
tune
climate models to understand present and future events, and the
response to
major perturbations of Earth's climate and the global carbon cycle,
Herrle
added.
Recommend this Article to a Friend Back to: News |
Subscribe to the Earth Observatory About the Earth Observatory Contact Us Privacy Policy and Important Notices Responsible NASA Official: Lorraine A. Remer Webmaster: Goran Halusa We're a part of the Science Mission Directorate |