The Chi‐Chi, Taiwan earthquake: Large surface displacements on an inland thrust fault

Huang

Nat. Hazards Earth Syst. Sci.

et al. 2008

Abstract. For the interpretation of the storm event-induced landslide distribution for an area, deterministic methods are frequently used, while a region's landslide susceptibility is commonly predicted via a statistical approach based upon multi-temporal landslide inventories and environmental factors. In this study we try to use an event-based landslide inventory, a set of environmental variables and a triggering factor to build a susceptibility model for a region which is solved using a multivariate statistical method. Data for shallow landslides triggered by the 2002 typhoon, Toraji, in central western Taiwan, are selected for training the susceptibility model. The maximum rainfall intensity of the storm event is found to be an effective triggering factor affecting the landslide distribution and this is used in the model. The model is built for the Kuohsing region and validated using data from the neighboring Tungshih area and a subsequent storm event -the 2004 typhoon, Mindulle, which affected both the Kuohsing and the Tungshih areas. The results show that we can accurately interpret the landslide distribution in the study area and predict the occurrence of landslides in the neighboring region in a subsequent typhoon event. The advantage of this statistical method is that neither hydrological data, strength data, failure depth, nor a long-period landslide inventory is needed as input.

Section: Regional Settings and Storm Eventsmentioning

confidence: 99%

Statistical approach to storm event-induced landslides susceptibility

Huang

Nat. Hazards Earth Syst. Sci.

et al. 2008

“…During the 1999 Chi-Chi, Taiwan, earthquake of magnitude M ⊂ 7.6, the observed ground-motion velocity near the northern end of the fault was extremely large (about 3 m/s-the largest ever recorded), but short-period acceleration was not particularly strong, so the damage to ordinary structures by shaking was minor. 13 The counterintuitive coupling of large ground-motion velocity with minor structural damage could be a manifestation of lubrication effects. However, since the Chi-Chi earthquake is the only one for which such large slip and slip velocity have been instrumentally observed, whether the counterintuitive coupling represents general behavior remains to be seen.…”

Section: Connecting Small and Large Scalesmentioning

confidence: 99%

The Physics of Earthquakes

Kanamori¹,

Brodsky²

2001

Physics Today

355

369

“…In the epicentral region, the crustal deformation was essentially a uniaxial compressional strain of 0.36 micro-strain/ year in the direction of 114°over several years before the earthquake . After the mainshock, more than 10,000 aftershocks were recorded in the first 3 weeks (Ma et al 1999).…”

Section: Chi-chi Earthquake and Co-seismicmentioning

confidence: 99%

Streamflow Changes in the Vicinity of Seismogenic Fault After the 1999 Chi–Chi Earthquake

Liu

Chia

Chuang

et al. 2017

Pure Appl. Geophys.

Abstract-Changes in streamflow have been observed at 23 stream gauges in central Taiwan after the 1999 M W 7.6 Chi-Chi earthquake. Post-earthquake increases, ranging from 58 to 833% in discharge, were recorded at 22 gauges on four rivers and their tributaries. The streamflow increase typically peaked in 2-3 days and followed by a slow decay for a month or more. An increased groundwater discharge to the river after the earthquake can be attributed to rock fracturing by seismic shaking as well as pore pressure rise due to compressive strain. A large decrease in discharge was recorded immediately after the earthquake at the gauge near the earthquake epicenter. Further analysis of long-term data indicates that the post-earthquake discharge at the gauge reduced to a level smaller than that at an upstream gauge for 8 months. Such a streamflow decrease might have been caused by a discharge to the streambed due to a co-seismic decrease in pore pressure induced by crustal extension during the rupture of the thrust fault.