An
earthquake that struck a densely-populated part of southeastern Turkey
and that was felt as far away as Israel and Cyprus was strong and shallow
enough to be lethal on a devastating scale, seismologists fear.
اضافة اعلان
Authorities in Syria and Turkey said at least 1,200 people have died and
expect the toll to rise.
The earthquake, one of two to hit the area, hit at 4:17am, according to
the US Geological Survey (USGS), and measured at magnitude 7.8. Quakes can be
far stronger, experts said, but what matters more than the numerical magnitude
is relative strength combined with location — whether many people live nearby —
and depth, or whether a quake is shallow enough to impact a wide area.
In a report issued about 30 minutes after the first earthquake, experts at
the USGS said there was a 34 percent chance of between 100 and 1,000
fatalities, and a 31 percent chance of between 1,000 and 10,000 fatalities.
“Extensive damage is probable and the disaster is likely widespread,” the
report said. It estimated economic losses of as much as 1 percent of Turkey’s
gross domestic product.
Januka Attanayake, a seismologist at the University of Melbourne in
Australia, said that the energy released by the earthquake was equal to about 32 petajoules, enough to power New York City for more than four days.
“In terms of energy, the magnitude 7.8 that occurred is 708 times stronger
than a magnitude 5.9,” he said, citing as an example an earthquake in
Melbourne, Australia, in 2021, in which some minor damage was sustained to the
city.
The strength of earthquakes is measured on a scale known as the local
magnitude scale. An earlier version was known as the Richter scale. It is a
logarithmic scale: For each whole-number it rises, the amount of energy
released by an earthquake increases by about 32 times.
But the potential damage of an earthquake depends on far more than its
magnitude, with the population density of a given area as well as the
shallowness of the epicenter both contributing to the level of devastation,
with a shallower quake holding the potential for more damage. This one was
about 10km deep.
Another important factor is the quality of construction of buildings in
the area. “The population in this region resides in structures that are
extremely vulnerable to earthquake shaking, though some resistant structures
exist,” the USGS report noted, adding: “The predominant vulnerable building
types are unreinforced brick masonry and low-rise nonductile concrete frame
with infill construction.”
In a post on Twitter, the seismologist Susan Hough of the USGS said that
the quake, while far from the strongest the world has seen in recent decades,
risked being particularly dangerous because of its location and shallow depth.
At the lowest end of the scale, a magnitude 1 quake would be a
micro-earthquake that is all but imperceptible to humans. A magnitude 7
earthquake has been described by seismologists as having “an energy equivalent
to around 32 Hiroshima atomic bombs,” as Renato Solidum, the director of the
Philippine Institute of Volcanology and Seismology, told the Times in 2013.
At magnitude 7.8, the earthquake in Turkey is classified as a “major”
earthquake. Other quakes of a similar magnitude have included a 2013 earthquake
in Pakistan, in which about 825 people died, and the April 2015 earthquake in
Nepal, when nearly 9,000 people died.
This earthquake appeared to be one in a series, said Attanayake, the
seismologist in Melbourne. A long fault line of roughly 1,500km, dividing the
Eurasian plate to the north from the Anatolian plate to the south, had produced
multiple earthquakes of magnitude 6.7 or greater since 1939.
Read more Region and World
Jordan News
.jpg)
.jpg)
