Evil-looking mile-wide cracks slicing across the seafloor off the coast of Virginia and North Carolina testify to past violence in the region. Neal Driscoll, a geologist at Woods Hole Oceanographic Institution in Massachusetts, recently startled many coastal residents when he announced a possible cause for the fissures. On a research cruise, he and his colleagues bounced sound waves off the ocean bottom near Chesapeake Bay and spotted reservoirs of buried, compressed natural gas. A disturbance might cause these gas reserves to blow, creating the cracks. If the event were big and fast enough, Driscoll says, it might trigger a submarine landslide and set off a tsunami.
Now a group at Pennsylvania State University has detected evidence of a similar upheaval along the Jersey shore. Graduate student Brandon Dugan and geologist Peter Flemings found a layer of high-pressure fluid trapped beneath the ocean bottom 100 miles off the coast of southern ...
