South Korea infrastructure worries earthquake experts
SEOUL — The good news: South Korea has not experienced a catastrophic earthquake in recent history and isn’t prone to them.
The bad news: The possibility of a damaging major earthquake exists and some experts doubt whether South Korean infrastructure could withstand it.
On Jan. 20, a 4.8-magnitude earthquake struck Gangwon province in northeast South Korea. It “was not a sign of activating seismic activity,” the Korean Meteorological Agency stated.
But predicting earthquake trends in Korea is tough because historical data goes back only about 40 years, said Lee Hee-il, top researcher at the Earthquake Research Center, an affiliate of the Korea Institute of Geoscience and Mineral Resources.
Korea is far less likely to be struck by a major earthquake than China or Japan, Lee said.
But experts appear most concerned about whether South Korea is prepared for even a moderate, shallow earthquake in a big city.
Much of the country’s infrastructure was built with no official consideration of earthquakes. Not until 1988 did South Korea enact construction laws and codes to protect buildings against collapse. In 1992, that law was extended to infrastructure, including roads and bridges.
But bribes and payoffs often are considered part of doing business in many South Korean industries; paying building inspectors for quick, unwarranted approvals wouldn’t be a surprise, Lee said.
“A lot of concerned voices (are) rising over whether the builders constructed earthquake-resistant buildings based on design plans meeting the standard of law,” Lee said. “It is indeed doubtful.”
An eight-month, $1 million study commissioned by South Korea’s government painted a doomsday picture should a 5.2-magnitude earthquake strike central Seoul at a depth of 16 miles.
More than 30,000 people would die and 60,000 buildings would be destroyed between Seoul and Incheon, the study projected.
However, Lee and multiple experts have strongly criticized the accuracy of the model, which Lee said didn’t factor in housing density, building standards or daily population movements.
A smaller 5.0-magnitude earthquake striking close to the surface in a large city would cause significant damage, Lee said.
Even the resulting shift in the earth’s crust from a big earthquake in Japan or China could heighten the chances of South Korea experiencing a powerful quake, experts say.
Chi Heon-cheol, a colleague of Lee, recently said because Fukuoka, Japan, was hit with a 7.0-magnitude earthquake in 2005, an earthquake of 5.0 magnitude or higher is more likely to strike Korea within the next five years, according to local news reports.
A shallow 6.0-magnitude or higher earthquake striking a metropolitan area is highly unlikely but possible, Lee said — but were the country to suffer an earthquake that large, “the possible damages and casualties would be awful beyond description.”
Still, massive temblors have struck Japan before without producing similar earthquakes in South Korea.
On Jan. 23, South Korea’s Cabinet Council passed legislation calling for the Korea National Emergency Management Agency to prepare new construction standards for more earthquake-resistant structures.
The measure also clarified law-enforcement roles during disasters.
Tracking temblor records
SEOUL — The highest magnitude earthquake to hit Korea since they began tracking them about 40 years ago was a moderate 5.3 in North Korea’s North Pyeongan province.
South Korea experienced a 5.2-magnitude earthquake 50 miles off the coast of Uljin, on the central east coast, in 2004.
And the Jan. 20 earthquake — measuring 4.8 — in Gangwon province was the eighth-largest recorded on record. It caused little damage, according to news reports.
Geologists consider anything under 5.0 to be light.
Earthquakes ranging between 5.0 and 5.9 on the Richter scale, which measures magnitude, are considered moderate, according to the U.S. Geological Survey.
Using the Mercalli scale, which measures intensity, earthquakes ranging between a Richter 5.0 and 5.9 can be expected to produce “damage negligible in buildings of good design and construction,” according to USGS.
Slight to moderate damage may occur in well-built, ordinary structures.
“Considerable damage” can be expected in poorly built or badly designed structures,” according to USGS.
— Erik Slavin