Quakefest!

For the past two years, Ruth Pelz, education coordinator at the Burke Museum, planned to open an exhibit dedicated to the theme of earthquakes in the Northwest. Halfway into the project, Pelz wondered if the public would be all that interested.

Then the Nisqually quake hit in February of last year, giving the Seattle community a rude wake-up call.

"Nature got the big message out for us," Pelz said. "Now we all know that we can have big earthquakes and that we can't afford to be complacent."

Last weekend, the Burke sponsored Quakefest, giving students and researchers at the UW a chance to share stories and experiences with children and their parents. The Burke earthquake exhibit opened Feb. 28, but the purpose of Quakefest was to teach children about earthquakes while having fun.

"Last month, we had an earthquake-preparedness workshop," said Cynthia Johnson, public-programs coordinator. "This weekend was geared toward the family. We tried to hit certain topics so the kids would have fun."

UW junior Paul Spitznas volunteers at the Burke exhibit on weekends. As a civil engineering major, Spitznas answers questions about how buildings respond to earthquakes.

Using plastic squares to represent buildings, Spitznas placed short and tall models on a conveyor belt to show what happens in an earthquake. When he turned the belt's speed to low, the taller plastic building began to sway. But when he cranked the speed to high, the shorter model began to shake crazily while the tall building moved only a little. The point of the exhibit is to show that depending on its height, each building has a different resident frequency, meaning some buildings might ride out a shallow earthquake but be destroyed by a deep earthquake, and vice versa.

"That can be changed pretty easily by adding crossbeams or changing the weight and height," Spitznas said as he put rubber bands around the tall building and added a paperweight to the small building. "The main point is that all buildings don't react the same to an earthquake."

His goal is to one day work in designing safer buildings in quake-prone cities like Seattle.

A big, hard-boiled egg

David Williams likes to describe the earth as being like a hard-boiled egg to his young audience. If the hot core of the planet is the hardened yolk, the mantle is the spongy egg white. The ground that we walk upon, known in science as the lithosphere, is the brittle shell floating on top of the other layers.

"Plate tectonics is one of the greatest ideas in science to understanding the world," said Williams, who has worked as both a science writer and researcher.

Right off the Washington coast, the Juan de Fuca plate is continually sliding beneath the North American plate. The oceanic plate is full of heavy elements like iron and manganese, which slides beneath the lighter North American plate. This process, called subduction, has created both the beautiful mountain ranges in Washington but also is responsible for earthquakes.

Williams described how the two plates could get stuck together like a Velcro zipper. Sometimes, gravity causes the oceanic plate to slip just a little toward the core. The resulting deep earthquake usually has an epicenter from 30 to 50 kilometers under the earth. This is what happened during the 2001 earthquake -- due to its depth, the quake was frightening yet caused little damage. The Pacific Northwest normally experiences deep quakes once every 30 to 40 years.

The "subduction earthquake" is far more dangerous, but fortunately, one should only take place once every 300 to 500 years. The oceanic plate may slide forward as much as 20 feet, generating what many geologists estimate could be a 9.0 on the Richter scale. Such a massive geologic event could last for several minutes and cause tsunamis and widespread devastation from Alaska to Northern California.

Seattle also has to worry about its own fault line that runs along Iinterstate 90 and right under Safeco Field. This fault zone was created by the San Andreas fault, which moves Oregon and Washington in a northwesterly direction. The ground around Seattle is scrunched against the bedrock of Canada, and Williams said that if the northwest movement remained unchecked, in a few million years Boeing Field would be located at the Seattle Center and be at the same altitude as Mount Baker. However, the Seattle fault releases the pressure in the form of shallow earthquakes that could do great damage to older brick buildings in downtown Seattle.

Although Williams' message about earthquakes was sobering, he hoped that the children left his class with a new appreciation for geology.

"Geology is all around us and that it's constantly affecting our lives -- that's a central theme of the program we teach at the Burke," Williams said. "Also, we've only understood the basic theory of plate tectonics for about 30 to 40 years. There's room for more exploration."

Do animals feel quakes before people do?

Mammals curator Jim Kenagy became an expert in animal behavior before and during earthquakes quite by accident. As a graduate student at UCLA in 1971, he was studying the habits of kangaroo rats from the Mojave Desert when an earthquake struck. The rats were very quiet during their normal hours of activity, yet suddenly began running on their exercise wheels in the morning hours when they should have been resting.

"Obviously, these animals were disturbed by the shaking of the earth," said Kenagy.

The reason why the animals probably knew about the quake ahead of time is that rodents have a much better sense of hearing than humans do and could detect the sound of the earth shifting. Other biologists theorize that certain species can react far faster to earthquakes than humans. For example, certain types of fish such as catfish and sharks have the ability to sense changes in the earth's electromagnetic field, a phenomenon that happens before major quakes. Kenagy mentioned that since dogs have a refined sense of smell, they may be warned about a quake by chemicals being released through small fissures in the ground.

After his preliminary research on the kangaroo rats, the U.S. Geological Service attempted a strange program to see if animals could be used to predict earthquakes. Farmers in central California were asked to watch their animals for any signs of strange behavior, then report it to a hotline. The program met with limited success.

"The humans turned out to be unreliable," Kenagy said. "There would be a small quake and people would call in after the fact."

Today, researchers rely upon electronic sensors to try and predict if a quake is coming. Unfortunately, the fiasco in the 1970s has kept scientists from further investigations into how animals respond to earthquakes.

"But the bottom line is animals do respond to earthquakes," said Kenagy.

Japanese folktale teaches important lesson

David Yamaguchi has always been interested in both scientific research and Japanese culture. His research into earthquakes and the tidal waves that they create has taken him to Japan numerous times.

Yamaguchi said that the Japanese coastline is well prepared for the tidal waves that could be triggered by quakes. For example, some towns have large walls both in their harbor and protecting the residential districts. Escape routes leading to higher ground are well marked, and everyone has been educated about what to do in case of a tsunami.

"This integrated system is what we don't have in America," Yamaguchi said. "Although we probably can't convince the public to build walls, we could do a lot to get everything in place, beginning with education."

On Saturday, Yamaguchi entertained the audience with an old folktale about Hamaguchi the old farmer. Hamaguchi lived high atop a fishing village in Wakayama, a peninsula not far from Tokyo. He was both the richest and wisest person in the village, which was why he became the village leader. One night, as the village prepared for the harvest festival, Hamaguchi looked out over the ocean and saw the waves slowly drawing back to the horizon. In the village, the people were too startled to react, but the wise Hamaguchi soon realized that the reason the waves had rolled back was because a tsunami was bearing down on the coast.

To draw the people to higher ground, Hamaguchi set fire to his bundles of harvested rice. All the villagers quickly forgot about watching the sea and headed up the hill to help put out the blaze. Only when everyone was assembled on the hill did the village leader explain why he had started the fire. At that moment, the tsunami struck - destroying the village but doing no harm to the people. For his bravery and wisdom, Hamaguchi became a Shinto god who the people prayed to for protection from earthquakes and tsunamis.

The story was written down and textbooks and became a cartoon in order to educate Japanese children about earthquake safety. Yamaguchi said that the Washington coastline is just as prone to being hit by tidal waves, yet many people do not know the warning signs.

"The idea is that there may come a time in these children's lives when they see the water pull back," said Yamaguchi. "What's really happening is that the water's being pulled into the tsunami. When you see that, you have to know to head for higher ground and stay there for at least a few hours."

"Earthquakes are inevitable and inescapable aspect of Northwest geology, so we should prepare our families to get through them safely."

The earthquake exhibit, The Big One, will continue to be on display until Sept. 2. Ruth Pelz said she hopes that events such as Quakefest will continue to raise the public's awareness about earthquakes.