Experts plumb depths of quake-causing cracks on the Pacific sea floor
VANCOUVER — New research focused off the west coast of North America is giving seismologists a better understanding of what one scientist describes as “the single greatest geophysical hazard to the continental United States.”
Zach Eilon, a geophysicist at the University of California Santa Barbara, has developed a new method that uses an array of scientific instruments spread across the sea floor to measure shock waves that travel through the planet’s crust.
The rate at which the waves lose energy, called attenuation, provides clues about rock temperatures deep below the surface of the Earth, which is important for understanding the friction that builds up between tectonic plates as they rub against one another, he said. The amount of friction affects the size of an earthquake created when the plates give way, as well as the destructiveness of an accompanying tsunami.
Eilon’s research targets the Juan de Fuca plate, which runs several hundred kilometres off the coast between southern British Columbia and northern California and is the youngest and smallest of the planet’s 13 major tectonic plates.