<html>
<font size=5 color="#FF0000"><b>Friday October 3, 12 Noon, 56-154 <br>
</font><font size=5 color="#800000">"Dynamics of the Ancient Carbon
Cycle"<br>
</font><font size=5 color="#FF0000">Professor Dan Rothman <br>
</font><font size=4 color="#FF0000">Department of Earth Atmospheric and
Planetary Sciences, MIT <br><br>
</font>Long-term changes in the Earth's carbon cycle are encoded in the
isotopic composition of carbon buried in ancient sediments.<br>
Extraordinarily large fluctuations in this signal occur in the geologic
era preceding the first great diversification of animal life. Analysis of
the geochemical records and construction of a simple model indicate that
these large fluctuations also precede a major dynamical transition, from
a carbon cycle evolving dynamically, far from steady state, to the slow
"quasistatic" evolution of a steady state. We suggest
that this transition reflects a fundamental reorganization of the Earth's
biogeochemical cycles.<br><br>
<br>
Pick up some lunch immediately before the seminar in 16-168.<br><br>
<br>
</b>Next Seminar: <br>
Friday October 10, 12 Noon, 56-154<br>
Professor John Grotzinger<br>
EAPS <br>
"Did Extinction at the Precambrian-Cambrian Boundary lead to the
Cambrian Radiation of Animals?"<br><br>
<br>
<x-sigsep><p></x-sigsep>
Matthew Gardner, Ph.D.<br>
Program Administrator<br>
Earth System Initiative, 16-177<br>
Massachusetts Institute of Technology<br>
Cambridge, MA, 02139<br>
617.253.6895<br>
<a href="http://web.mit.edu/esi" eudora="autourl">http://web.mit.edu/esi</a></html>