From 1960 to 1990, scientists have observed a 1.3% per decade decline in the amount of sun reaching the Earth’s surface. This phenomenon, coined “solar dimming,” is due to changes in clouds and air pollution that are impeding the sun's ability to penetrate. Scientists believe that the combination of growing quantities of man-made aerosol particles in the atmosphere and more moisture have caused the cloud cover to thicken.
News and Events
May 14, 2004
March 12, 2004
Finding the epicenter of earthquakes has not changed in principle since the 1930s -- after closely examining seismograms from different widely-spaced listening stations, researchers decide on the arrival times of various seismic waves and calculate an approximation. In practice this can result in errors of several miles
February 05, 2004
The Hudson River Estuary, a stretch of the Hudson River from Troy, N.Y. to its mouth in New York Harbor, has begun a new stage of its life say geologists at Columbia University's Lamont-Doherty Earth Observatory and Queens College in Flushing, N.Y. Researchers at both institutions have found that, aside from a few very specific locations, the estuary may have largely stopped filling in with new sediment.
January 05, 2004
Columbia University researchers have found that steel dust generated in the New York City subway significantly increases the total amount of airborne iron (Fe), manganese (Mn) and chromium (Cr) that riders breathe. The airborne levels of these metals associated with fine particulate matter in the subway environment were observed to be more than 100 times greater than levels observed in home indoor or outdoor settings in New York City.
December 18, 2003
Scientists at the University of California, Riverside and Columbia University have found evidence of the release of an enormous quantity of methane gas as ice sheets melted at the end of a global ice age about 600 million years ago, possibly altering the ocean's chemistry, influencing oxygen levels in the ocean and atmosphere, and enhancing climate warming because methane is a powerful greenhouse gas.
October 30, 2003
The atmosphere and the oceans carry on an exchange of carbon dioxide (CO2), a major greenhouse gas. This is particularly significant in the equatorial Pacific Ocean because it is one of the most important yet highly variable natural source areas for the emission of CO2 to the atmosphere.
Lamont Researchers Discover Currents Connecting Pacific and Indian Oceans Are Colder and Deeper Than ExpectedOctober 24, 2003
Scientists at Columbia University’s Lamont-Doherty Earth Observatory have found that currents connecting the Indian and Pacific Oceans are colder and deeper than originally believed. This discovery may one day help climate modelers predict the intensity of the Asian monsoon or El Niño with greater accuracy and with more lead-time than is currently possible.
Lamont Doherty Researcher Develops New Use For Seismic Reflection Data: Revealing Locations And Potentials For Mega EarthquakesAugust 08, 2003
Researchers have found an important new application for seismic reflection data, commonly used to image geological structures and explore for oil and gas. Recently published in the journal Nature, new use of reflection data may prove crucial to understanding the potential for mega earthquakes.
May 02, 2003
Detailed analysis of regional and teleseismic waveform data from the June 18, 2002, Evansville, Indiana earthquake indicates that the earthquake occurred at a depth of about 18 km (±2 km).