Stories tagged earthquakes

Feb
17
2010

The Enriquillo fault: Only the western half of the Enriquillo fault ruptured during Haiti's January earthquake.
The Enriquillo fault: Only the western half of the Enriquillo fault ruptured during Haiti's January earthquake.Courtesy Mikenorton
Haiti’s January 12th earthquake occurred on a strike-slip fault that runs in an east/west direction through the country. The fault, known as the Enriquillo fault, is where the North American and Caribbean tectonic plates meet. The jostling of these plates caused a quake that measured 7.0 on the Richter scale, killed approximately 217,000 people, destroyed 280,000 residences and commercial buildings, and left over one million people homeless. It has been deemed the most destructive natural disaster that a single nation has endured. Unfortunately, geologists believe that another, equally destructive quake could occur in Haiti within the next 20-30 years. Using high-resolution radar images of the Enriquillo fault after the quake, geologists from the University of Miami found that only half (the western half) of the fault had surged. They speculate that the remaining energy still locked up in the earth is what will cause the next quake on the eastern portion of the fault.

The radar images also showed that the earthquake produced a lot of vertical motion, not typical in strike-slip faults. This vertical motion, say geologists, explains how such a small fault movement could cause such a large earthquake. From their analysis, geologists are recommending that Haiti move all of its essential infrastructure (schools, hospitals, etc.) north, out of the fault zone.

This is a great example of science being used to help avoid future devastation, or at least lessen future destruction. Knowing that there is still potential danger along the Enriqillo fault allows people to plan accordingly (i.e. building or rebuilding in a safer location). However, this is also a case where I hope science is wrong.

A powerful earthquake (magnitude 7.9) hit near the Pacific island of Samoa this afternoon. The Pacific Tsunami Warning Centre has issued a warning for the Samoa Islands, New Zealand, Tonga, Fiji, and other Pacific islands as far away as Hawaii.

Mar
06
2009

Zipingpu Dam: Upriver from the town of Dujiangyan, Sichuan, China.
Zipingpu Dam: Upriver from the town of Dujiangyan, Sichuan, China.Courtesy TaylorMiles
Scientists suspect that last year’s devastating earthquake in China may not have been a natural disaster. A nearby dam may have weakened fault lines and spurred the magnitude-7.9 quake.

The Zipingpu Dam is only 3.4 miles from the epicenter of the May 12, 2008 earthquake in Sichuan province. This quake killed 80,000 people and left 5 million homeless. Although the area exhibits a lot of seismic activity, an earthquake of this magnitude is unusual.

Water in the Zipingpu Dam

The Zipingpu Dam is one of nearly 400 hydroelectric dams in the area. It rises 511 feet high and holds 315 million tons of water. US and Chinese scientists believe that the weight of the water increased the direct pressure on the fault line below. This volume of water would exert 25 times more pressure annually than is natural. Additionally, water seeping into the rock acted as a lubricant and relaxed the tension between the two sides of the fault line. Since the reservoir was filled in 2004, the water caused a chain of ruptures culminating in this massive earthquake.

Worldwide impact on green energy

Sichuan province is the epicenter for more than just a powerful earthquake. It is here that most of China’s hydroelectric power is generated, an integral component of its renewable power plans. The area also produces much of the world’s wind turbine equipment. The infrastructure will take months or years to repair.

Before the quake, China admitted to major flaws in the country’s 87,000 dams. The earthquake damaged other dams and power stations and several major reservoirs were drained to prevent their dams from failing.

Nov
23
2008

Columbia's Nevado del Huila region
Columbia's Nevado del Huila regionCourtesy USGS/R.L. Schuster
The eruption of a volcano in southern Columbia has claimed the lives of at least 10 people and officials fear the death toll will rise.

Nevado del Huila is the highest volcano in Columbia, towering at 17,602 feet. Early last year It came to life after being dormant for more than 500 years.

The volcano is located in a remote area of southeastern Columbia about 150 miles south of Bogota. A number of isolated villages surround the mountain, and thousands were evacuated earlier this week for fear of an impending eruption.

When the eruption finally happened yesterday, it triggered two large landslides along the Paez River. Seven people are still listed as missing and the region remains on high-alert. But the locals have good reason to be nervous. In 1994 several hundred people were killed by landslides from Nevado del Huila induced earthquakes. And nine years before that a nearby volcano named Nevado del Ruiz erupted and killed more than 25,000 people.

LINKS

Story source
Volcano info at the USGS

My homepage: This is my homepage with a couple of the mentioned gadgets.
My homepage: This is my homepage with a couple of the mentioned gadgets.Courtesy Joe
If you are interested in tracking hurricanes, typhoons, tropical storms, etc. there is a cool gadget available for your Google hompage (and probably others) that allows you to view, track and interact with maps that show the most current active of these tropical weather systems. Its an interesting way to keep up and monitor the systems - and remind yourself that they happen all over the world. The one I use is here but I am sure there are others that are similar.

There are also gadgets for earthquakes, volcanoes and even one specific to world disaster photos.

May
12
2008

i just want to tell my observations..every morning from march to june of 1991 i observed some unusual formations of the clouds... and then 6.5 mag. of earthquake striked... that was here in the philippines..and then every now and then i can see and observed those unusual formations of clouds... i can say that there would be an earthquake but i can;t tell when is the exact place and the exact date will it strike...