We're closer to the elusive prize of predicting an earthquake, but not on the fault that caused the 1906 San Francisco quake, says CSUF Associate Professor of geology David Bowman. "We've had one of the world's best seismographic records in California since 1932. Since then, there have been four major earthquakes," Bowman says. "But none of them are on the San Andreas fault," which triggered the San Francisco temblor. This lack of activity makes predictions difficult.

Bowman studies how earthquakes alter geological stress around faults, and how those stresses change after and even just before earthquakes. Many quakes are preceded by what scientists call "accelerating seismicity." Increasing pressure around faults, and small but increasing movements in the ground, hint where a quake might occur. But Bowman thinks he can turn these movements into an earthquake prediction model. "We still can't measure the stress directly and our model isn't well developed, but it might eventually point to a specific rupture or fault for the next quake," he says.

But it's difficult to determine how much stress does the trick. "We can tell how much stress has changed after an earthquake, but what do we know about the total stress of a fault? You'd have to know the billion-year history of the fault," Bowman says.

Nobody has that information. No truly systematic data was compiled anywhere in the world before 1900. So, instead of looking at what stresses may be occurring now, Bowman looks at previous earthquake data to see if his models would have predicted that older quake.

"We know where the big faults are. But instead of saying, 'is this fault stressed?' we are asking 'where should the quake have been?'" says Bowman. "Instead of predicting, we're 'post-dicting,' in a way that may yield clues to true prediction." Bowman and his students have studied hundreds of faults, and have made successful connections with recent quakes in Baja California, and earlier quakes, like the 1994 Northridge quake.

On the morning of Dec. 26, 2004, Brady Rhodes' career took something of a detour. A very large earthquake off Indonesia triggered a tsunami, a so-called "tidal wave," that killed thousands along the coast of the Indian Ocean. Two days later, Rhodes, Fullerton professor of geology, was in Thailand.

Rhodes normally looks at movements of the earth's plates (a process called tectonics) in Thailand and southeast Asia. Millions of years ago, the Indian subcontinent's plate collided with the plate carrying Asia, forming the Himalayan mountain chain. These movements often cause earthquakes, but the Indian Ocean region wasn't an area suspected of having current tsunamis. "The area hadn't had a historic tsunami. Most research in tsunamis area is in Japan, the northwest United States, Chile and the northeastern Atlantic Ocean," says Rhodes. Since the 2004 event, Rhodes and his colleagues in Thailand look for evidence of ancient paleo-tsunamis, by studying soil deposits. "We think we've found evidence of ancient tsunamis in Thailand," he says. "We are working on that right now."

When Rhodes arrived in Thailand, his team looked over the entire area affected by the tsunami. "The Thais wanted to set up warning zones and immediate alarm systems. I pushed for work in paleotsunamis. The Thais weren't as interested in that. But the only way to know how often tsunamis occur is to go back into the past."

Nearly all tsunamis are triggered by earthquakes, but volcanic activity and underwater landslides can cause them, too. Now, Rhodes is examining sediment samples from the Indian Ocean disaster and comparing them with sediments from suspected paleotsunamis. Beach sand and other coastal rocks that are too far inland are one major clue to ancient tsunamis, but the researchers have to rule out other processes that also deposit these sediments. "People haven't really looked at the tropics for evidence of tsunamis," Rhodes says. "But this should tell us how much to prepare for the next one."

Assistant Professor Brandon Brown, one of Fullerton's newest geologists, studies volcanoes. While volcanoes and earthquakes are caused by different underground movements, they often erupt and shake, respectively, in the same place. Most volcanoes are located on the edges of the planet's tectonic plates, which grind, bluntly collide or submerge one under the other as they shift over the earth's surface. Others can form over earthquake faults.

One source of volcanoes arises from submerging (or subducting, as it's formally known) plates. As earth subducts, it heats into magma. Browne studies how this magma is stored under the earth's surface until it erupts through a volcano.

"I study what temperatures trigger an eruption, how deep the magma has to be, and why things seem to be quiet until there's an eruption," Browne says.

Browne's focus is on smaller volcanoes, like those located around Mammoth Mountain or Lone Pine. "There are volcanoes all around there," he says. "There are two faults in the area, which allow magma to come up to the surface. Magma always looks for the least difficult way up," he says.

By examining the rocks in the area, Brown tries to determine how eruptions occur. He performs experiments with erupted rocks, subjecting them to different temperatures and pressure (usually high amounts of both). Then, he can match the rocks with physical data in volcanic areas. "Minerals grow layers, just like tree rings, with every event. You can then apply these techniques to ancient eruptions to see when, and how often, they happened."

Brown believes that by conducting enough experiments on magma flows and magma storage under areas like Mammoth, predictions could improve. "It's an expensive problem, and nobody else is doing it."

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