Bracing for the big one
November 2, 2003
The fear a catastrophic earthquake is imminent is more prevalent in Japan than concerns about a terrorist attack.
To study and better prepare for seismic activity, Japanese central and local governments, scholars and experts, private companies and individual homeowners are spending billions of dollars annually.
Experts say the cost is worth it because quake prediction is improving.
There are several regions where scientists keep watchful eyes on underground activity that could cause major earthquakes.
“A list predicting earthquakes that might occur in the next 30 years is available,” said Keiji Doi, assistant professor at the Earthquake Research Institute of University of Tokyo. “Of course, it is the nature of earthquakes to occur at unexpected times and places.”
Doi believes there will be a major earthquake within three decades.
“Off the coast of Miyagi prefecture is the highest possibility of an earthquake with 98 to 99 percent probability,” he said, adding the temblor would likely be named Miyagi Oki Earthquake.
The region in northern Honshu was jolted twice this year when two earthquakes with registered magnitudes of 7.0 and 6.4 occurred in May and July, respectively; 851 people were injured.
“Those two earthquakes originated from activities of an inner part of a tectonic plate and an inland fault,” he said. “The earthquake yet to come is expected to occur on the boundary of two tectonic plates under the water.”
Such an earthquake — of magnitude 7.0 to 7.5 — with an underwater epicenter could cause a tsunami, he said.
Tectonic plates surrounding Japanese archipelago constantly collide with each other, releasing energy and causing earthquakes, Doi said.
“Two tectonic plates, Pacific plate and South Philippine Sea plate, are slowly moving, sliding underneath the land plates where Japan sits,” he said.
Earthquakes occur when the plates shift, he said, adding three of the plates meet beneath the Kanto Plain and Tokyo.
“Of all earthquakes occurring around the world, 10 percent occur around Japan,” he said.
Another “highly probable” massive quake talked about and feared for decades is the predicted Tokai Earthquake.
According to a long-term earthquake prediction issued by the Earthquake Research Committee of the Ministry of Education, Culture, Sports, Science and Technology, there is a 10 percent probability the quake will hit within 10 years. There is about a 50 percent probability it will strike within 30 years.
“There were two major earthquakes in the area in 1944 and 1946,” said Mitsuyuki Hoshiba, chief of the Earthquake Prediction Information section at the Japan Meteorological Agency.
When those earthquakes occurred, one of three troughs near Japan — Nankai Trough — was left unbroken.
“The trough that should have been split 60 years ago is still there,” Hoshiba said, noting it could snap at any moment.
The Tokai Earthquake is predicted to have a magnitude of at least 8.0.
When it hits, Shizuoka, Aichi, Kanagawa, Yamanashi, Gifu and Nagano would be severely affected, he said.
“Twenty-four hour monitoring system is set up throughout the region to catch any premonitory symptoms and to minimize damages,” he said.
Quake survival checklist
Those who’ve lived in Japan realize the island nation has more than its fair share of earthquakes, including major temblors that result in serious injuries and fatalities.
Japan’s propensity for earthquakes reminds some Americans here of another location known for seismic activity: California.
Experts in the California Governor’s Office of Emergency Services offer a thorough checklist of emergency supplies that should be on hand during a powerful earthquake and its disruptive aftermath.
They recommend having enough supplies to last at least 72 hours.
Here are the supplies they recommend:
• One gallon of water per person per day (a week’s supply is preferable)• Water purification kit• First-aid kit and book• Food and non-electric can opener• Blankets or sleeping bags• Portable radio, flashlight and spare batteries• Essential medications• Extra pair of eyeglasses• An extra set of house and car keys• Fire extinguisher• Food, water and restraint (leash or carrier) for pets• Cash and change
• Formula• Bottle• Pacifier• Soap and baby powder• Clothing• Blankets• Baby wipes and disposable diapers• Canned food and juices.
• Large plastic trash bags, tarps and rain ponchos• Large trash cans• Bar soap and liquid detergent• Shampoo• Toothpaste and toothbrushes• Feminine hygiene supplies• Toilet paper• Household bleach
Safety and comfort
• Sturdy shoes• Heavy gloves• Candles and matches• Light sticks• Change of clothing• Knife or razor blades• Garden hose for siphoning and firefighting• Safe, sturdy tent• Communication kit with paper, pens, stamps
• Plastic knives, forks and spoons• Paper plates and cups• Paper towels• Heavy-duty aluminum foil• Camping stove for outdoor cooking
• Axe, shovel and broom• Adjustable wrench• Tool kit with a screwdriver, pliers and a hammer• Coil of ½-inch rope• Plastic tape, staple gun and sheeting for window replacement• Bicycle• City map
For more information on surviving an earthquake, log on to the California Governor’s Office of Emergency Services Web site at www.oes.ca.gov