Public Lectures Spring 2010



Sunday, March 28, 2010

Detecting and Measuring Landslides with Seismology

>>CLICK HERE to watch the video from this lecture.

Göran Ekström, Ph.D.
Professor, Department of Earth and
Environmental Sciences at Columbia University

Detecting and Measuring Landslides
with Seismology

 

Landslides and avalanches generate seismic waves just like earthquakes, and we can use the tools of earthquake seismology to detect and locate these potentially disastrous events, sometimes sooner than communications reach the outside world. Last year’s devastating typhoon Morakot triggered several massive landslides on Taiwan, some of which involved more than 10,000 tons of rock and mud avalanching at speeds of 100 mph down mountain slopes. We are gaining new insights into these events by studying their seismic signatures.

Landslide photo credit: Peter von Gaza

 


 

Sunday, April 11, 2010

Currents, Conveyors, and Climate Change

>>CLICK HERE to watch the video from this lecture.

Jerry McManus, Ph.D.
Professor, Department of Earth and Environmental Sciences at Columbia University

Currents, Conveyors, and Climate Change

Interconnected ocean currents move water, salt, and heat around the Earth, influencing today’s global climate. Evidence suggests this system of “rivers in the sea” was different in the past, and that changes in its strength and configuration were associated with the dramatic climate changes of the ice ages. Yet other large climate influences, like the amount of seasonal sunlight and atmospheric greenhouse gas concentrations, often varied at the same time, making it hard to isolate the primary cause. Putting together some new and existing evidence from deep-sea sediments suggests that shifting ocean currents did drive dramatic climate change, especially in and around the North Atlantic Ocean. Could it happen again?

 This lecture is sponsored by the Lamont-Doherty Alumni Association.


     

Sunday, April 18, 2010

Dust in the Wind: Dust, Stardust, and Earth’s Climate System


Gisela Winckler, Ph.D.
Doherty Research Scientist, Lamont Doherty Earth Observatory
Adjunct Associate Professor, Department of Earth and Environmental Science, Columbia University

Dust in the Wind: Dust, Stardust, and
Earth’s Climate System


Maybe you’ve heard that some of the dust particles that fall on your backyard come from the Sahara, but did you know that some also come from outer space? Each year, about a billion tons of desert dust and 40,000 tons of cosmic dust rain down on Earth. Scientists analyze sediment cores from the deep ocean and ice cores from the Antarctic ice sheet to reconstruct the history of dust deposition, going back millions of years to determine what role dust played in the climate system. These results have a wide variety of implications, including findings that bear directly on the potential of current proposals to seed oceans with iron-rich dust in order to mitigate global warming.


 

Sunday, April 25, 2010

Rockland County’s Water Resources

>>CLICK HERE to watch the video of this lecture

Paul Heisig, Hydrologist
U.S. Geological Survey

Rockland County’s Water Resources


Where can Rockland County look for water to support future growth? And how healthy is its bedrock aquifer? Paul Heisig of the U.S. Geological Survey will present the results of a five year assessment of Rockland County water resources.  This report was initiated by NYS Assemblywoman Ellen Jaffee in 2004 following reports that groundwater withdrawals were nearing estimated recharge rates. After the presentation, a panel of Lamont scientists will discuss their research on local water issues followed by a Q & A moderated by colleague Meredith Golden. Panelists will include: Stuart Braman on water use and conservation potential; Steve Chillrud on groundwater surveys for arsenic; Brad Lyon on historical precipitation and drought patterns; and Martin Stute on groundwater ages.

*NOTE: This will be a two-hour presentation with live video feed to the Comer Building if seating capacity is exceeded.