Tag: seismology4
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Retrieving Instruments from the Deep
Over the first 22 days aboard the R/V Marcus G. Langseth, we’ve zigged and zagged our way over a 360×240 mile region of the Pacific plate, first dropping instruments to the seafloor, and then shooting airguns to them (see previous posts). The final step is to recover a subset of the instruments: 34 ocean-bottom seismometers…
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The Art of Sound in the Ocean
The NoMelt experiment aims to image the structure of an oceanic plate, including its deepest reaches up to 70 km beneath the seafloor. One of our primary means to do so is to create sound (acoustic) waves in the ocean from the ship, and record those waves at receivers on the seafloor, after they have…
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Deploying Instruments on the Seafloor in the Deep Ocean
Oceanic plates are born at mid-ocean ridges, where hot mantle rocks are brought very close to the surface, partially melt, and then cool and crystallize. The newly formed rocks move outwards from the mid-ocean ridge, making way for the next batch of hot rock rising from below. Inch by inch, over millions of years, oceanic…
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Rolling into Open Water in the Central Pacific
We nicknamed our project NoMelt because we seek to characterize a mature, pristine oceanic plate far from its volcanic origin at a Mid-Ocean Ridge, and away from areas of pronounced volcanism and melting that subsequently alter the structure of the plate. Our site in the central Pacific fits these scientific needs. However, one downside is…
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Probing an Oceanic Plate
Everything that we understand about the rhythms of the Earth’s surface – the slow growth of mountain chains, the creeping expansion of the ocean basins, the abrupt upheaval of a major earthquake, the explosive eruption of a volcano – is viewed through the context of plate tectonics. This simple yet highly successful model for describing…
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Paul Richards Wins Seismological Society of America’s Reid Medal
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…
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Witnessing the Desperation of the Poor
At the moment the Haiti earthquake struck, two Earth Institute staffers were in Port-au-Prince assessing how to make the country less poor, and less vulnerable to natural disasters. Marc Levy and Alexander Fischer of the Center for International Earth Science Information Network were working with the Haiti Regeneration Initiative, a nascent program to repair Haiti’s…
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Needed in Haiti: Reinforced Buildings—and Economy
The Jan. 12 Port-au-Prince earthquake is almost unique in modern history. It is about the worst natural extreme to affect some of the worst-off people on earth. What does disaster recovery mean when this happens? Poor countries suffer more from natural extremes like hurricanes, droughts and floods than do rich countries. Everything about richer countries…
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Haiti: America’s ‘Teachable Moment’
President Obama is providing the leadership we need and hoped for in the face of the horror of the Haitian earthquake. The clearest evidence of American unity behind the effort to respond to the tragedy in Haiti took place at the White House on Saturday, Jan. 16, as Obama joined forces with two ex-presidents to…
