“Scientists at Los Alamos National Laboratory have found that most moderate and large earthquakes are preceded by tiny earthquake clusters, sometimes even weeks before the main shock, according to theLA Times.
HUGE EARTHQUAKE IN BOLIVIA REVEALS VAST UNDERGROUND MOUNTAIN RANGE BIGGER THAN ANYTHING ON EARTH’S SURFACE
“On 9 June 1994, an 8.2 magnitude tremor rocked a sparsely populated region of the Amazon in Bolivia. Nothing this powerful had been seen in decades, with shocks being felt as far away as Canada.
“Earthquakes this big don’t come along very often,” says geoscientist Jessica Irving.
Not only was it big, it was deep, with a focal point estimated at a depth of just under 650 kilometres (about 400 miles). Unlike quakes that grind through the crust, the energy from these monsters can shake the whole mantle like a bowl of jelly.”