The intensity of the Haiti earthquake that killed nearly 500,000
people has left experts intensely surprised, with the magnitude 7
quake being touted as the strongest earthquake in more than two
centuries.
“It’s quite strange from a historical perspective,” the National
Geographic Daily News quoted Julie Detton, a geophysicist with the
U.S. Geological Survey, as saying.
Haiti is part of the island of Hispaniola, which also hosts the
Dominican Republic. The last major earthquake to strike Haiti’s side
of the island was in 1860.
Tuesday’s initial earthquake, which struck at about 5 p.m, spawned
dozens of aftershocks, about 15 of which were magnitude 5 or
greater.
“It’s not something that we can project is going to happen. But
definitely if you’re moving two [plates] in one area, you’re
building up stress and strain in another,” Detton said.
According to the report, the Haiti earthquake was caused by the
release of seismic stresses that had built up around two tectonic
plates.
The motions of these plates create what are known as strike-slip
faults, where two sections of Earth’s crust are grinding past each
other in opposite directions, it adds.
“The Caribbean plate is moving eastward with respect to the North
American plate,” Detton said.
When the stresses along the fault lines reach a certain point, they
can be released in bursts of energy that cause earthquakes, although
it’s unclear when the energy will be discharged as a series of small
quakes or as one big temblor.
Since Haiti is very close to the boundary where the Caribbean and
North American plates meet, fault lines linked to the plates’
movements run right through the country, Detton said.