Seismology

During Hurricane Sandy the seas rose a record 14-feet in lower Manhattan. Water flooded city streets, subways, tunnels and even sewage treatment plants. It is unclear how much sewage may have been released as plants lost power or were forced to divert untreated wastewater into the Hudson River.

Lamont-Doherty Earth Observatory director G. Michael Purdy has been named Columbia University’s executive vice president for research. Taking over as interim director of the observatory is associate director Arthur Lerner-Lam.  The moves, effective Feb. 1, were announced by Columbia president Lee Bollinger and Earth Institute director Jeffrey Sachs in emails to staff  Jan. 19.

In a research career spanning more than four decades, Paul Richards, a seismologist at Lamont-Doherty Earth Observatory, has helped uncover Earth’s inner structure and advanced techniques for detecting nuclear explosions to ensure that bans on nuclear testing can be enforced. Richards will receive the Seismological Society of America’s Harry Fielding Reid medal at its annual luncheon on Wednesday, April 21.

The earthquake that struck Haiti took place along what is called a strike-slip fault—a place where tectonic plates on each side of a fault line are moving horizontally in opposite directions, like hands rubbing together. When these plates lock together, stress builds; eventually they slip; and this produces shaking.

Seismologists, Pinpointing Location, See Little Doubt It Was Bomb  

Seismologists who have intensively studied North Korea’s nuclear testing efforts say Monday’s blast was certainly a nuclear bomb, roughly five times larger than the country’s first test in 2006.

Ordinarily, losing almost all of one's instruments would be considered a severe setback to any scientist. But when Maya Tolstoy, a marine geophysicist at the Lamont-Doherty Earth Observatory and the Earth Institute at Columbia University, recently learned that two-thirds of the seismometers she placed on the floor of the Pacific Ocean were trapped more than 8,000 feet (2500 meters) underwater, it turned out to be an extremely good sign.

When the sea floor off the coast of Sumatra split on the morning of December 26, 2004, it took days to measure the full extent of the rupture. Recently, researchers at Columbia University's Lamont-Doherty Earth Observatory analyzed recordings of the underwater sound produced by the magnitude 9.3 earthquake.

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.