China Earthquakes

Tangshan, 1976

Overview

Earthquake in China Tectonic overview

- Causes of Earthquakes

– Damage– Recovery

China Tangshan Earthquake

July 28th, 1976 Time: 3:42 AM local Magnitude: 7.8 Location: Under the

city Tangshan, China. East of Beijing.

Causes of Earthquake China

Earthquake occurred on the fault Tancheng-Lujiang (Tan-Lu) a fault zone, or collection of parallel faults.

China is being squeezed as the Indian plate (India) that moves northeastward and the Eurasian plate (Asia) squeezing it from the west.

Damage China Damages was caused

directly by the shaking of the quake.

The fault ruptured at a depth of 11 km (7 mi)

Fatalities: 242,419 Majority of Destruction was

in Tangshan city. The fact that it was in the middle of the night when most people were sleeping.

Building codes were lenient. After shock 16 hours later

measuring above M 7.0.

Recovery

Rescue efforts were complicated by the time of the event.

Lack of power throughout the city. Poor building codes led to many

deaths. Many were rescued but not until

hours or days later.

1. Government established prediction as a goal in 1966– a. Especially valuable goal since many buildings are unsafe– b. widespread involvement of people

2. The Feb. 4, 1975 Haicheng quake was predicted– a. 7.3M with widespread damage

– b. Great reduction in loss of life

– c. Changes in physical parameters

• (1) Rapid rise in elevation and ground tilt

• (2) Fluctuation in Earth's magnetic field

• (3) Foreshocks

• (4) Groundwater fluctuations

• (5) Erratic animal behavior

3. Notable failures– a. July 27, 1976 Tangshan quake - no prediction

• (1) >650,000 dead and about 780,000 injured

– b. May 29, 1976 west Yunnan Earthquake 6.9M– c. False predictions

• (1) Kwangtung - August, 1976

Papua New Guinea July 17th , 1998 Time: 6:49 PM local Magnitude: 7.1 RS Location: 20 KM off

the North Central Coast of New Guinea (So. Pacific Ocean)

Causes of Earthquake PNG Arc-continent collision

of the Pacific and Indian Australian plate boundary. North Bismark and Pacific Plates are colliding beneath the India-Australia Plate Margin. Converging 70mm per year with a lateral shear between plates of 100 mm per year.

Damage PNG Damage was caused

indirectly by submarine landslide triggered by the shaking. (Tsunami 7 to 15 meters height, 40 km coast line)

Fatalities: 3,000 estimated

Majority of destruction was in coastal communities. Those whom died were mostly children.

Recovery PNG

Donations were made by the Red Cross, United States, and other international organizations.

Monetary contributions and relief grants that focus on rebuilding communities, and mitigation activities that may help to reduce the impact of similar events in the future.

1. www.geocities.com/CapeCanaveral/Lab/1029/Tsunami1998PNG.html2. http://walrus.wr.usgs.gov/tsunami/high_res.html3. http://walrus.wr.usgs.gov/tsunami/PNG.html#Background