MAGNITUDE 6.3 EARTHQUAKE STRIKES TAIWAN (7:02 pm, October 31, 2013)

MAGNITUDE 6.3 EARTHQUAKE STRIKES TAIWAN

(7:02 pm, October 31, 2013)

Walter Hays, Global Alliance for Disaster Reduction, Vienna,

Virginia, USA 

LOCATION MAP

7:02 PM, OCTOBER 31, 2013

• At 7:02 pm, a magnitude 6.3 earthquake occurred 45 km (28 miles) south-southwest of the coastal city of Hualian.

• The shallow depth of 12 km (7.5 mi) exacerbated the ground shaking.

• Buildings over a wide area, including Taipei, the capital city, were shaken.

EACH EARTHQUAKE IS AN OPPORTUNITY TO ADD TO THE “GLOBAL BOOK OF

KNOWLEDGE” ON OCCURRENCES,

CONSEQUENCES, AND DISASTER RISK

REDUCTION MEASURES

A NOTE ON THE PASTA magnitude 7.6

earthquake in central Taiwan in 1999 killed

2,416 people

M 7.6

Shallow depth (about 2 km)

1:47 am

SEPTEMBER 21, 1999

JI JI, TAIWAN EARTHQUAKE

BASED ON REPORTS BY USGS, EERI, ASCE/TCLEE, MCEER, TAIWAN

AGENCIES, AND OTHERS

• The 1999 Taiwan earthquake was a subduction zone earthquake caused by interaction of the Philippine plate with the Eurasian plate.

EARTHQUAKE FAULT

• The quake was generated by slip on the Chelongpu fault.

PHYSICAL EFFECTS: GROUND SHAKING

• Strong motion records showed that ground shaking was characterized by long-period energy related to the magnitude and local site conditions.

• It was several times greater than the level prescribed in the building code.

SOCIOECONOMIC IMPACTS

• 44,338 buildings collapsed, and an additional 41,336 houses and buildings were severely damaged.

• Twenty 10- to 20-story residential buildings either collapsed or experienced significant damage, suggesting frequency-dependent site amplification.

• Strong ground shaking from the main shock and its large aftershocks caused the collapse of a few mid-rise buildings in Taipei, the capital, which is located about 140 km north of the epicenter in a deep alluvial basin.

• Strong ground shaking, ground failure, and surface fault rupture caused power outages and severe lifeline damage.

• Some examples of lifeline damage had not been observed in other earthquakes..

• The loss of power had wide ranging effects, including disruption of Taiwan’s semi-conductor fabrication facilities.

• The regional compression caused thrust faulting.

• Over 60 km of surface faulting with lateral and vertical displacements reaching 9 m and 5 m, respectively, occurred in the center of the Island.

• Most of the bridges that suffered significant damage were located in the area bounded by two thrust faults that ruptured the surface.

• Liquefaction caused damage in a residential neighborhood of Yuanlin located in Changhua County.

•Extensive liquefaction-induced damage was also observed in parts of Taichung Harbor.

SOCIOECONOMIC IMPACTS

• The death toll reached 2,416.

•11,446 were injured.

• Economic losses reached $9.2 billion.

• Short-term global stock market prices were influenced by impacts on the semi-conductor industry.