Since the 921 Earthquake in 1999, scientists have thrown everything into identifying predictors of the devastating phenomenon, looking beneath the ground and even from space in a bid to improve understanding of the mechanisms responsible.
Standing beside a monitor detecting crust deformations at National Dong Hwa University in Hualien last year, National Central University geophysicist Yen Horng-yuan (
According to Yen, studies of past earthquakes suggest there is an association between the phenomenon of advance crust deformation and the onset of earthquakes.
PHOTO: CHIU YU-TZU, TAIPEI TIMES
"By carrying out continuous monitoring, we can analyze an abundant amount of data to find out where the crust begins to change before the occurrence of an earthquake. This data might be useful for research on predicting quakes," Yen said.
By the end of 2006, another 30 stations will be set up around the country to complete the GPS network, he said.
Taiwan sits atop the junction of the Philippine plate and the much larger Eurasian plate. The former is slowly being forced beneath the latter under the northern stretches of the country. The process, referred to by seismologists as subduction, is also being monitored by local geophysicists.
Since August 1998, Lee Jian-cheng (李建成), an associate research fellow at Academia Sinica's Institute of Earth Sciences, has measured crust change with creepmeters set up at Tapo Elementary School in Taitung County, which lies on the active Chihshang Fault (池上斷層).
Creepmeters measure the displacement between areas located on opposite sides of a fault.
Lee said that research suggests the Philippines and Eurasia plates are converging at a speed of 8cm per year. However, Lee's continuous monitoring of the plate suture zone in the Huatung Valley connecting Hualien and Taitung suggests that the fault has contracted between 15cm and 20cm annually over the past five years.
"We are seeing significant fault activity here. So we will continue to study how the fault interacts with others nearby in the valley," he said.
The 200km-long Chihshang Fault is only one of seven active faults to have been discovered in the Huatung Valley. In 1951, two earthquakes resulting from dramatic fault activity here ruptured the surface and changed its topography all the way from Hualien to Taitung. At some locations, the land was raised by 75cm.
To better understand these faults' behavior, National Taiwan University geosciences professor Chen Wen-shan (
"Faults in this valley are regarded by scientists as the most active in Taiwan. By analyzing layers in the trenches we can study the old earthquakes that they caused, and we might develop ideas on predicting future activity," Chen said.
Prior to the 921 Earthquake, which claimed more than 2,400 lives, most Taiwanese had grown less concerned about the occurrence of a devastating temblor.
But a number of earthquakes of similar destructive force did occur earlier last century. The 7-magnitude Meishan Earthquake in 1906 killed more than 1,250 people in the country's southwest. A 7.4-magnitude earthquake in 1935 centered in the Hsinchu-Miaoli area killed over 3,200 people; a 6.5-magnitude aftershock then killed another 2,700.
In the wake of the 921 Earthquake, which also injured more than 8,700 people and left 100,000 people homeless, the National Science Council boosted funding for earthquake-related research. Seismologists, geologists and physicists have since teamed up on innovative projects in a bid to discover signs of when the next one will strike.
Scientists have for years speculated that electromagnetic phenomena might be connected to seismic activity. Now, local physicists have decided to look to space to gather more clues.
Liu Jann-yenq (
After analyzing data of more than 300 earthquakes in Taiwan between 1994 and last year with magnitudes greater than 5, Liu found that for 70 percent of the quakes, ionospheric electron density fell sharply to around 65 percent of the normal level some time in the five days before the temblor.
Liu said that if the magnitude was 6 or higher, around 80 percent of sampled quakes had the same effect.
"We're only trying to find precursors to earthquakes. It doesn't mean we've already established a theory for a mechanism of earthquake prediction," Liu said.
However, he said, the drop in ionospheric electron density did not correlate entirely with the occurrence of earthquakes because other causes of change in electron density are known to exist.
Chen Chau-huei (陳朝輝), a seismologist at National Chung Cheng University, told the Taipei Times that local resources for seismology research remain limited. He said there were only 30 professionals delving into earthquakes.
"Actually, Taiwan can be a leading focus of seismological research because the environment in which we live is actually a natural museum for earthquakes," Chen said.
NATIONAL SECURITY: Authorities are working to confirm the identities of the military personnel involved and investigating possible illegal conduct and regulatory violations Authorities are probing possible national security implications after Kinmen police and immigration officers on Sunday found a Chinese woman allegedly posing as a tourist while engaging in prostitution involving more than 10 military personnel. The woman, surnamed Chen (陳), has since been deported, authorities said, adding that investigators are still working to confirm the identities of those implicated, as the records only listed code names and aliases. The case stemmed from a report received by the Kinmen District Prosecutors’ Office on Friday last week from the Jinhu Precinct of the Kinmen County Police Bureau. On Sunday, police, along with the National Immigration
GLOBALGIVING: ‘ Caving to external pressure is not acceptable for an organization that has cultivated justice reform and human rights for 30 years,’ one NGO said A slew of non-government organizations (NGOs) have withdrawn from the GlobalGiving fundraising platform after it announced it would use “Chinese Taipei” instead of “Taiwan” from next month. The Taiwan Good Rice Association wrote on Facebook on Friday that it was informed on April 28 via a teleconference call of the change, which was made because the platform wanted to operate in China. Taiwan Good Rice is to terminate all cooperative relationships with GlobalGiving in response to the platform’s “unilateral and non-negotiable” decision to remove references to Taiwan, the NGO said. “Taiwan is in the official name of Taiwan Good Rice Association and the
HEAVY WEATHER: Typhoon Jangmi is due to crash straight into the Ryukyus as airlines look to shift flights to larger aircraft or cancel flights to Okinawa entirely Taiwan’s international air carriers announced flight adjustments over the weekend as Typhoon Jangmi is forecast to hit the Ryukyu Islands today and tomorrow. The Central Weather Administration (CWA) upgraded Jangmi from a tropical storm to a typhoon at 8am yesterday, with the eye located 580km south of Naha city. It was moving north at 19kph. Today, China Airlines’ CI-120, CI-121, CI-122 and CI-123 flights between Taoyuan and Naha, Okinawa, have been canceled as well as CI-132 and CI-133 between Kaohsiung and Naha. EVA Air’s BR-112, BR-113, BR-186 and BR-185 flights between Taoyuan and Naha are also canceled. Low-cost carrier Tigerair Taiwan canceled IT-230,
Chinese Nationalist Party (KMT) Chairwoman Cheng Li-wun (鄭麗文) yesterday briefed her party’s Central Standing Committee regarding her scheduled visit to the US between Monday next week and June 16, saying that her purpose would be to persuade the US that the Republic of China (ROC) Constitution was a “one China” constitution that would foster stable and peaceful cross-strait relations. The ROC Constitution is the most important defense for all Taiwanese citizens, as it upholds our democracy and has contributed to our robust economy, which aligns with international and US interests, she said. “We would not be troublemakers and drag the US under,”
RSS