Spatial distribution of PEGS signal strength during the Tohoku quake in 2011, shortly before the arrival of the primary seismic wave. Credit: Earth and Planetary Science Letters, Vol 536, Zhang et al. 2020, Prompt elasto-gravity signals (PEGS) and their potential use in modern seismology”,, with permission from Elsevier.  ENLARGE […]

Mount St. Helens Volcano Nearly 40 years ago, analog data tapes faithfully recorded intense seismic activity in the two months before the historic eruption of Mount St. Helens in Washington State in May 1980. It took some lengthy and careful restoration efforts–including a turn in a kitchen oven for some […]

Credit: CC0 Public Domain The casual observer could be forgiven for thinking the Caribbean is shaking itself apart. Tuesday’s massive 7.7 magnitude earthquake just south of Cuba and north of Jamaica comes on the heels of the 6.4 magnitude quake that hit Puerto Rico and the U.S. Virgin Islands earlier this month. […]

Thomas L. Pratt, a scientist with the United States Geological Survey, changes data cards in earthquake monitoring and recording equipment amid aftershocks across the island’s southern coast where recent quakes have toppled homes and schools in Ponce, Puerto Rico, Tuesday, Jan. 14, 2020. The seismic activity that experts say is […]

The Arecibo Observatory in Puerto Rico boasts the world’s second-largest single radio dish (Image: © Arecibo Observatory/NSF) HONOLULU — Staff at Puerto Rico’s iconic Arecibo Observatory are monitoring the facility for potential damage in the midst of a spate of earthquakes rocking the island. The strongest of those quakes was a 6.4 […]

The Cullinan diamond was mined in Premier Mine in South Africa in 1905. The same mine has yielded superdeep diamonds, which could hold secrets to the quakes occurring in the mantle’s transition zone. (Image: © Public Domain) SAN FRANCISCO — Deep under Earth’s surface, earthquakes rumble in the mantle’s transition […]