访谈录 2010-03-01&0304 智利地震与海地地震有关？（在线收听）

Today's massive earthquake following the 7.0 quake in Haiti just last month and others recently around the globe, leave us wondering if there is a pattern and more trouble ahead. We’ll get some answers from NBC News Chief Science Correspondent, Robert Bazell.

Chile today. Haiti last month. When deadly earthquakes appear one after another, people always ask, is there a connection? (“This is a very, very…”) Seismologists say no, there are earthquakes all the time.

"This sense that we are having a lot of big ones close together, these are not actually related, they involve different places of plates."

Plates, those are huge sections of the Earth’s crust that are in constant motion. The boundaries where they meet are called faults. And when enough pressure builds, the faults slip violently, resulting in an earthquake. At the site of today's quake, one piece of Earth called the Nazca Plate, is constantly pushing underneath another called the South American Plate. It is part of an enormous system of faults surrounding the Pacific Ocean, called the Ring of Fire. Today's earthquake was just 150 miles north of the biggest earthquake ever recorded a magnitude 9.5 that killed 1600 people in 1960 and sent huge tsunamis around the Pacific.

"Almost half way around the world from this earthquake…"

The numbers used to measure an earthquake's magnitude don't tell the whole story. Today's 8.8 quake was far more powerful than the one that struck Haiti January 12.

"It would produce about 500 times as much energy as a magnitude 7. So this is a much larger earthquake."

Still all everyone expects the death toll in Chile to climb, many say it will fall far a short of the more than 200,000 killed in Haiti, where the earthquake struck right beneath a densely-populated, poorly-built area.

"Fortunately, the fault surface ruptured in this is a bit further from populated areas than the fault that ruptured in Haiti. So the overall shaking felt in populated areas is less. "

And the tsunami warnings? When an earthquake strikes under the ocean, a tsunami occurs when the ruptured fault moves violently up and down. Today's quake moves 350 miles of ocean forward, displacing so much water the scientists predicted the waves would travel as far as Japan and Russia.

Robert Bazell, NBC news, New York.