Earthquakes weaken the earth's crust

A series of earthquakes rocked New Zealand in 2010, 2011 that could weaken the earth's crust.

New Zealand is located along the "dangerous volcanic belt" , which is a narrow area around the Pacific, which generates about 90% of earthquakes worldwide. In 2011, a 6.3-magnitude earthquake shook New Zealand's South Island, with the epicenter very close to the country's second largest city, Christchurch. As a result, 185 people died, about 100,000 buildings were destroyed. This is the most terrible disaster ever hit New Zealand, damaging about 1/6 of the nation's GDP in the southern hemisphere.

Roads in Christchurch are seized by seismology - (Photo: Schwede66)

In fact, the 2011 earthquake was just the aftershock of a 7.1 magnitude earthquake that occurred 172 days ago (in 2010) in the same area, causing millions of dollars in losses. infrastructure and make 2 people seriously injured. Although the 2010 earthquake was stronger than the aftermath, it caused less damage due to the epicenter located far from the cities. Not stopped yet, the seismic seismic in 2011 continued with a series of other aftershocks. Scientists at GNS found that most earthquakes in New Zealand in those two years emitted large amounts of energy, matching the signals emanating from cracks in the faults of Earth's crust.

To learn more about the seismic sequence, experts began to study the rock beneath the earthquake area, called the Canterbury plateau . The results show that at a depth of 10 km below the plateau Canterbury is a huge , powerful volcanic rock known as the Hikurangi plateau , which has been reclaimed to about 100 million years deep when part of the earth's located on the edge of the ancient supercontinent Gondwana. It still sticks to the crust after so many years. Scientists conducted seismic wave analysis before and after the earthquakes collected by GeoNet, an earthquake measurement system throughout New Zealand. Based on data, including seismic waves originating from more than 11,500 seismic after the 2010 earthquake, they constructed a three-dimensional structure of volcanic rock beneath the Canterbury plateau, similar to the ultrasound scanning in the fetus.

Previously, the scientific community said that the power of the earth's crust could not be degraded due to aftershocks. However, the results of the study indicate that these tremors can lead to widespread thinning along the cracks in this crust, according to the Nature report. It can be said that this is the first time experts have observed such a situation, since it rarely happens. Now researchers continue to focus on seismic risk analysis in the region following continuous activity in the crust of South Island in New Zealand.