美캘리포니아주 강진 이후 총 8만회 여진…"화산지대 가까워"br br The two massive earthquakes that hit California recently have sparked more than 80-thousand aftershocks in the Ridgecrest area since July 4th.br Experts say the aftershock sequence from the 6-point-4 and 7-point-1 tremors is starting to slow down.br The Ridgecrest earthquakes are especially worrying as they are relatively close to the Coso Volcanic Field - one of America's largest producers of geothermal power.br Officials add the aftershocks have been creeping into areas close to two major earthquake faults,... which could lead to a quake of magnitude 8 or higher.