Prof explains science behind tsunamis

The tsunami that occurred on Dec. 26, 2004, was anything but a normal occurrence. It left us with many unanswered questions. Why did it happen? Could another one occur? What can we do to counter this natural disaster?

These are exactly the questions that Earth and Environmental Science professor Gomaa Omar answered during a presentation to approximately 45 students on Thursday night at the Weiss Tech House.

He began by explaining the geology that results in a tsunami.

The huge waves are caused by earthquakes, which occur due to the collision of tectonic plates. The plates build up energy for millions of years by pushing against each other. Eventually, one plate may slip under another, causing an earthquake -- as was the case in the recent tsunami.

When the plates slip, all the energy that is contained in them is released in a matter of seconds. In the Dec. 26 tsunami, the Indian plate slipped under the Burma plate.

This tsunami was of such great magnitude because of the extremely large area of the plate that slipped. The plate slip lifted five to six kilometers of water. Omar stressed that "water does not like suddenness," explaining that the effects of sudden movement in water are substantially greater than those of gradual movements.

Our usual conception of waves can not be used to appropriately describe tsunamis.

"Tsunamis are not tidal waves!" Omar said. "They are a wall of water with a huge amount of energy."

The magnitude of these waves actually caused the pens on seismographs -- the devices that measure vibrations in the earth -- to cut the paper.

At first, the water at beaches around the Indian Ocean receded for approximately half of a mile, which is an indication of an impending tsunami. According to Omar, people were better off at sea because the waves were broader and not as high.

In the aftermath of the horrifying event, much effort has been spent on learning how to improve warning systems.

"This was a very bad event, but it gave us a lot of information," Omar said.

There is a warning system in place in the Pacific Ocean, but none exists in the Indian and Atlantic oceans because earthquakes are not as common there. New warning devices, which measure water pressure, have been developed and utilized in the Pacific Ocean.

Attendees appeared satisfied with the lecture and were also treated to Thai cuisine halfway through the speech.

"You get so much bias from the media, it is nice to get objective science information, and Omar is one of my favorite professors," College sophomore Catherine Griffin said.

The organizers of the event, Engineering junior Mudit Jaju and College freshman Evan Richter, asked Omar to do the presentation because "geology is getting a lot of air time now, and it was important to teach students about technical prevention."

Please note All comments are eligible for publication in The Daily Pennsylvanian.