Nepal has been hit with a magnitude 7.3 earthquake,
and aftershocks as strong as magnitude 6.3 are still being felt. It has
been just over three weeks since the magnitude 7.8 earthquake hit the
country, leaving more than 8,000 dead, scores injured and millions
Sadly, scientists had predicted that another
earthquake was coming—and many more will come in the future in this
seismically active region.
The Himalayan region had been overdue an
earthquake, since the last one that hit Kathmandu 80 years ago.
During the earthquake on April 25, however, not all of the pent-up seismic pressure was released. This left room for more earthquakes in the near future.
That near future, however, could have been
days—or years—away. Predicting the precise location and timing of an
earthquake is not possible. There are simply no signals from the
movement of the Earth’s crust that can definitely point to when a quake
And then one occurred today, about 18km below
the surface and east of Kathmandu. It is not clear yet if this quake has
indeed released all the remaining pent-up pressure.
The movement of the Indian plate, which collided
with the Eurasian plate and gave birth to the Himalayas, makes the
region a seismic hot zone. On average, the Indian plate moves about 18
millimeters towards the Eurasian plate and slips underneath it. This
movement loads up some of its energy into earthquake faults, which
extend on a line from east to west, and the process is much like loading
energy in a spring. And every so often that energy is released in snap,
resulting in an earthquake.