As at least nine nations searched for the missing following the world's biggest earthquake in 40 years, geologist Gianluca Valensise of the Italian Institute of Geophysics and Vulcanology spoke with NEWSWEEK's Eric Pape Monday about the shifts in the earth's tectonic plates that sparked a 9.0 quake and a 33- to 40-foot-high wave that blanketed thousands of miles of Asian, Indian and African coastlines with death and destruction.
NEWSWEEK: Is it true that this quake shook the entire world?
Gianluca Valensise: After a major earthquake, the whole world resonates like a bell that has been struck. It lasts for several hours after the main shock. But what's more intriguing is that a big piece of the planet's mass has been moved around. This actually altered the axis of the earth's rotation.
Is that normal for a quake?
The 1960 earthquake (that registered 9.5 on the Richter scale) in Chile did it. The 1964 earthquake (a 9.2 on the Richter scale) in Alaska, too. And both created tsunamis.
What about other events, like say the detonation of a nuclear bomb?
This quake was more powerful. It has been calculated that the energy released on Sunday was 23,000 times that of the explosion of the nuclear bomb at Hiroshima (Japan). A large portion of the earth's crust--1,000 km (620 miles) in length by 100 km (62 miles) in width running from Western Sumatra to Myanmar--moved. And that is where they are feeling the aftershocks now.
Aside from the massive tsunami, was there anything unique about this quake?
The size. But the rest was pretty much expected. It is a highly seismic region. There have been other giant quakes just a bit to the south in 1994, and in the 1930s. It is a highly seismic region.
How would you compare this quake to others of the last decade?
It's just so much bigger. The Bam earthquake in Iran a year ago that destroyed a very vulnerable city (and killed more than 26,000) was much smaller. But this earthquake will not be famous for the shaking, it will be known for the tsunami, which is pretty unusual.
The risks of tsunamis have been greatly underestimated. A tsunami can travel 3,000 or 5,000 km (1,900-3,000 miles), in this case to regions like Somalia where people died on the beach because they had no idea that there had even been an earthquake. This is something that people will have to face in the next few years.
How fast can such a wave go?
In the open ocean, it can travel as fast as 800 kilometers (500 miles) per hour--like a commercial airplane--so it took two or three hours. This leaves time for a system to warn people, but there wasn't one in place.
What was the most awesome about this quake?
Its biblical nature. Its biblical size. And that it spanned two continents. The effect of the tsunami was made worse by the fact that so many people live on the coast, tourism is near the coast, and airports are at low elevations. Television reports show damage largely limited to people within a few miles of the coastline. Inland there are few problems. This is a new phenomenon. If people lived 100 meters (330 feet) above the sea, there would have been few casualties.
Should people in tsunami zones move away from the coast?
They feel desperate now because they fear it will happen again, but they will probably forget about these fears in a year or so, as people do, so there must be international pressure to create a warning system.
If a quake this magnitude hit on land, how would it have been different?
First of all, on land, you wouldn't have the tsunami. Then, depending on whether it was close to a large city, it would have destroyed it--or done nothing. In the high mountains of Tibet, there are 8.5s that change the landscape, but they don't kill anyone. Earthquakes like the one yesterday, in a subduction zone, have a repeat time of 200 or 300 years. A subduction zone is where one plate flows under another--in this case the Indian plate flows under the Burma plate. Subduction zones have the fastest repeat times in the world.
Could we see another huge earthquake in the near future?
This was so large that it consumed all of the stored energy in the area. We are recording aftershocks, but no one is expecting another humongous one.
The chance of a massive aftershock?
Very low. We are recording magnitude 6s and a few larger than that, but an 8 on the Richter scale seems unlikely in the same region--unless this quake triggers one in a different area. Some people are saying that another one is more likely to the southeast of Sumatra, in the coming days or weeks--but it probably wouldn't be as big. This was the fifth largest of the last century.
What are the most likely spots for another monster quake or a tsunami?
The ring around Sumatra toward the east and Japan. It is where the largest tsunamis in the world strike. The region where 95 percent of the earth's seismic activity is released and where there are the most active volcanoes is part of a band spanning from Myanmar, around Sumatra to the southeast toward the Sea of Japan, Alaska and the Western U.S., and then south toward New Zealand.
Can people in some of the world's poorest countries really prepare for this kind of quake?
Moving away from the coastline isn't very feasible. Tourism also has to be on the coast or people wouldn't go. People should expect their governments to do something. If governments don't do something, there's no hope. The kind of poor people who were affected far from the epicenter often don't even know what happened. It is like an ocean wave that isn't related to anything that simply comes and kills you. You can react to a normal earthquake with its standard shaking, you can make your house stronger--and then you might survive. But this felt more like an omen.