Has anyone successfully predicted an earthquake? Very few earthquakes have been successfully predicted. In 1975, near Haicheng, China, 90,000 people were evacuated a few hours before an earthquake that destroyed 90 percent of the buildings. The prediction was based on unusual animal behaviour and a number of small earthquakes (foreshocks) that suddenly stopped. However, scientists wrongly predicted a major quake in Kwantung Province, and for two months millions of people lived in tents before authorities decided the prediction was wrong.
4:26 PM
19.12.02
Frequency of earthquakes worldwide Over the last century, an earthquake with a magnitude of 8 or higher has occurred on average once each year. The planet averages 18 earthquakes with a magnitude of 7 to 7.9 each year, and 120 earthquakes with a magnitude of 6 to 6.9.
2:13 PM
13.12.02
Volcanic tremor Volcanic tremor is a distinctive type of ground vibration that can be measured by seismographs. Tremor can be produced by hot volcanic gases passing through cracks on the way to the surface and by the movement of molten rock below and within a volcano. Volcanic tremor is sometimes an early indicator that a dormant volcano is on the way to renewed activity.
1:56 PM
11.12.02
The average annual cost of damage from flooding in New Zealand exceeds the average annual cost of damage from earthquakes and volcanoes put together. Damaging storms occur much more frequently than damaging earthquakes and volcanic eruptions. 6:24 PM
29.11.02 The summit of Egmont/Taranaki volcano has wholly or partially collapsed at least five times in the last 130,000 years. Some debris slid up to 45 km from the volcano, and the resulting avalanche deposits are up to 4 m thick at the outer edge. 6:23 PM
22.11.02 How many earthquakes happen in New Zealand each year?
The Institute of Geological & Nuclear Sciences measures about 10,000 to 15,000 earthquakes in New Zealand each year. Most are too small to be felt and we only know they occur because they are recorded by seismographs. Each year New Zealand has about 100 to 150 earthquakes that are big enough to be felt. 6:22 PM
15.11.02 Twice during July sea level dropped by about half a metre. Both times it lasted for about a week and was recorded by instruments at Kaikoura, Sumner in Christchurch, Timaru and on the Chatham Islands. Scientists at the National Institute of Water and Atmospheric Research (Niwa) think the phenomenon may have been caused by a series of intense storms hundreds of kilometres south of New Zealand. Sea level rises under low-pressure storm centres, and the rising sea level far to the south may have sucked in water from the New Zealand region, causing the drop in sea level along the South Island coast. 2:45 PM
