In the early morning hours of September 21, 1999, a devastating earthquake
struck the central region of Taiwan. This earthquake became known as the 921 earthquake or
the "Ji-Ji" or "Chi-Chi" earthquake. The magnitude of the 921
earthquake was MS = 7.6 (Richter scale) or ML = 7.3 (the system used in Taiwan). There
were two large aftershocks of ML = 6.8 that occurred about 30 hours and 120 hours after
the main shock. An ML = 5.3 aftershock was recorded as late as 260 hours later causing
collapses of already damaged structures. As of October 1999, the death toll stands at more
than 2,400, with over 10,000 people injured. Approximately 10,000 buildings/homes
collapsed and over 7,000 more were damaged. In addition, there was widespread destruction
and disruption of lifelines, including roads and bridges, communication systems, water and
gas supply systems, and electric power systems.
Shortly after the earthquake occurred, MCEER
arranged to visit the devastated area through the National Center for Research on
Earthquake Engineering (NCREE), located at the National Taiwan University in Taipei,
Taiwan. NCREE hosted a workshop for MCEER researchers and others to identify short-term
strategies/actions for post-earthquake restoration and research needs. MCEER researchers
were paired with NCREE researchers with similar specialties, and the joint reconnaissance
teams examined the earthquakes impact. Their initial observations and impressions
are reported in the MCEER/NCREE Response, which can be accessed from our web site
at http://mceer.buffalo.edu/research/taiwaneq9_99/default.asp.
More comprehensive studies have since been carried out by NCREE. These reports are
in Chinese, and are listed in the Selected Bibliography section of this report.
This report contains observations from this
reconnaissance trip and workshop. It is the product of many authors representing several
disciplines and, while not a final assessment of the topics addressed, represents a
preliminary earthquake engineering evaluation of the natural, built and social
environments. The observations and conclusions herein form a springboard for future
collaborative research efforts between MCEER, NCREE and other colleagues, in our common
goal to create earthquake resilient communities throughout the world.
|