They have leveled buildings, flattened cities and villages, killed people around the world and caused up to $20 billion worth of damage at once. The culprits? Earthquakes, whose work can be seen in the form of vast destruction and mayhem.
Just last week, a quake estimated at 7.9 on the Richter Scale hit western India, crushed the city of Buhj and its surrounding villages and caused an estimated 13,000 deaths. Such tragedy only adds to the terror that comes along with the word earthquake and raises the question, "Can that happen to us?"
Virginia has had its share of quakes and tremors, though as many as California and other West Coast states that rest on the edge of the Pacific and North American Plate.
|
Although the largest earthquake ever to hit Virginia was the third-most powerful to hit the eastern United States in 200 years, the Commonwealth still is considered only a "moderate" risk state by the United States Geological Survey.
But earthquakes in other areas of the world suggest Virginia may be susceptible to large earthquakes. Western India is not considered a "high-risk" area, yet still experienced a 7.9 magnitude quake last week.
"There is an analogy between that of the eastern United States" and western India, said Virginia Tech Geosciences Prof. Arthur Snokes. Since the East Coast is approximately the same distance from a fault as western India, it "is good to understand what happens even if you are not on a plate boundary, or even 100 miles or so from it."
However, Environmental Science Research Prof. Grant Goodell said the chances of an earthquake rocking the University are almost none,
"The last major earthquake [in this area] was in 1875, over in Sussy County, where it knocked over a few chimneys, that's all," Goodell said. "It measured about a 5.6" on the Richter Scale.
The start of a quake
An earthquake first begins deep in the earth and occurs along a fault, a fracture in the Earth's rock foundation.
The Earth's individual continental plates also are known as seismic zones, which shift according to the atmosphere. When stress builds up on both sides of the fault, the Earth's crust will break as the rock snaps, sometimes resulting in a tremor.
Central Virginia is home to two seismic zones, one in Giles County and another extending from north of Albermarle County by way of the James River to Richmond.
A quake also may occur on a fault line - distinct from a fault - which is the edge of a continental plate. The famous San Andreas fault line caused the massive Bay Area earthquake of 1989, the most expensive quake in the United States, costing nearly $20 billion in damages.
Although Virginia has not experienced any major earthquake damage, it is not immune to the Earth's tremors. In fact, the last shock in the area was in April 2000, when two minor earthquakes struck the Goochland-Chesterfield area. Both quakes measured approximately 2.5 on the Richter Scale.
"They were mild little things," said Environmental Sciences Prof. Thomas Biggs. "Californians would think it was a truck driving past."
The University, unlike Virginia Tech, does not have a department focused only on seismology. Until the late 1960s, the University had a geology department, but it expanded the department in the early 1970s to include the study of hydraulics, the atmosphere and ecology.
Snokes said studying seismology is important, even in Virginia.
"This is a global society, we worry about many things that are not in our own homes," he said. Earthquakes "can happen and it has happened."
Predicting a quake
Meanwhile, the development of protective technology to predict an earthquake has been slow.
Predicting the location of an earthquake is hard - it is like "predicting where lightning will strike," Goodell said.
The most that can be done is to estimate where a quake "could happen and build accordingly to minimize the damage should an earthquake actually occur," Snokes said.
The uncertainty of predictions partially is due to the nature of an earthquake, which causes damage by releasing a vast amount of energy when a rock breaks along plates in the earth. The energy, in the form of vibrations known as seismic waves, begins deep in the earth and can break strong rock such as granite at 2 miles per second on average.
At that rate, a fracture in the rock can spread more than 350 miles in one direction in less than three minutes. With such a short period of time, the odds are slim that geologists can foresee the occurrence of an earthquake, much less its effects.
Read More
Honor Committee considers formal ban of AI detectors as evidence in trials
By Lexie Stadler | 5 hours agoThe Committee also addressed balancing student perspectives with those of Committee representatives during panel discussions.
Pro-Palestinian protesters form encampment near University Chapel
By CD News Staff | 6 hours agoThe encampment overlapped with a separate “May Day” protest on the Lawn, which was hosted by student activist group U.Va. Dissenters and the U.Va. Apartheid Divest Coalition.
Another aggravated assault incident reported to UPD
By Thomas Baxter | 6 hours agoThis is the first community alert of May.
