7.5 Magnitude Earthquake hits Afghanistan; Death Toll Rises

Today, a 7.5 magnitude earthquake strikes Afghanistan, at 4:05am CT, but 1:39pm in Afghanistan. The epicenter is located 158 miles north-northeast of the Capital Kabul, Afghanistan; and 28mi north of `Alaqahdari-ye Kiran wa Munjan, Afghanistan.

The United States Geographical Survey (USGS) issued an orange alert for the earthquake,
which is issued for shaking- related fatalities. The USGS says "significant casualties are likely and the disaster is potentially widespread. Past events with this alert level have required a regional or national response." Concern is also high because of the types of structures in the area. The USGS saying, "Overall, the population in this region resides in structures that are highly vulnerable to earthquake shaking, though some resistant structures exist."

Death tolls are hard to know for sure, because communications are down in many places, but it is known in the province Khyber Paktunkwa, in Pakistan, according to the provincial disaster management authority there, the death toll is up to 106, and 652 are injured.

It is also known that at least 11 young girls were killed in a stampede while trying to exit their school in Takhar Province, while many others were injured, according to Dr. Abdullah.

The map below shows how widespread the resulting shaking was felt:

But what caused this massive quake? The USGS says its because of reverse faulting at intermediate depths. "Approximately 210 km below the Hindu Kush Range in northeastern Afghanistan. Focal mechanisms indicate rupture occurred on either a near-vertical reverse fault or a shallowly dipping thrust fault. At the latitude of the earthquake, the India subcontinent moves northward and collides with Eurasia at a velocity of about 37 mm/yr." The USGS also states that these active faults and the resulting earthquakes are the direct result of the convergence between the India and Eurasia plates.
This collision is causes uplift that produces the highest mountain peaks in the world including the Himalayan, the Karakoram, the Pamir and the Hindu Kush ranges."

Here is the rest of the write up on the tectonic summary for the region done by the USGS:

"Earthquakes such as this event, with focal depths between 70 and 300 km, are commonly termed "intermediate-depth" earthquakes. Intermediate-depth earthquakes represent deformation within subducted lithosphere rather than at the shallow plate interfaces between subducting and overriding tectonic plates. They typically cause less damage on the ground surface above their foci than is the case with similar magnitude shallow-focus earthquakes, but large intermediate-depth earthquakes may be felt at great distance from their epicenters. "Deep-focus" earthquakes, those with focal depths greater than 300 km, also occur beneath northeastern part of Afghanistan. Earthquakes have been reliably located to depths of just over 300 km in this region.
Seven other M 7 or greater earthquakes have occurred within 250 km of this event over the preceding century, the most recent being a M 7.4 earthquake in March 2002 just 20 km to the west of the October 26, 2015 event, and with a similar depth and thrust fault orientation. The 2002 event caused over 150 fatalities and the damage or destruction of over 400 houses in relation to an associated landslide."


For more details on the earthquake click here.
All images courtesy of USGS.