Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC  

Pakistan

A  magnitude  7.7  earthquake  occurred  in  south-­‐central  Pakistan.  The  earthquake’s  epicentre  was  located  69  km  north  of  Awaran,  Pakistan,  and  270  km  north  of  Karachi,  Pakistan.  The  event  occurred  at  a  depth  of  20  km  (12  miles)  and  shaking  was  felt  as  far  away  as  Karachi,  Hyderabad  and  Delhi.  

So  far,  30  deaths  have  been  confirmed  by  local  authoriNes,  with  houses  reported  to  have  collapsed  in  some  areas.  However,  due  to  the  earthquake’s  remote  locaNon,  details  on  casualNes  and  damage  are  currently  unclear.  

 

 

 

 

 

Shaking  intensity  

Very  strong  shaking  (VII)  in  the  nearby  town  of  Awaren;    strong  shaking  (VI)  in  the  large  town  of  Kharan;  rather  strong  shaking  in  Hyderabad,  and  moderate  shaking  in  Karachi.  

Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC  

I. Instrumental

Not felt by many people unless in favourable conditions.

II. Weak Felt only by a few people at best, especially on the upper floors of buildings. Delicately suspended objects may swing.

III. Slight Felt quite noticeably by people indoors, especially on the upper floors of buildings. Many to do not recognise it as an earthquake. Standing motor cars may rock slightly. Vibration similar to the passing of a truck. Duration estimated.

IV. Moderate Felt indoors by many people, outdoors by a few people during the day. At night, some awakened.

V. Rather Strong

Felt outside by most, may not be felt by some people in non-favourable conditions. Dishes and windows may break and large bells will ring. Vibrations like train passing close to house.

VI. Strong Felt by all; many frightened and run outdoors, walk unsteadily. Windows, dishes, glassware broken; books fall off shelves; some heavy furniture moved or overturned; a few instances of fallen plaster. Damage slight.

VII. Very Strong

Difficult to stand; furniture broken; damage negligible in building of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. Noticed by people driving motor cars.

VIII. Destructive

Damage slight in specially designed structures; considerable in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture moved.

IX. Violent General panic; damage considerable in poorly designed structures, well designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.

X. Intense Some well build wooden structures destroyed; most masonry and frame structures destroyed with foundation. Rails bent.

XI. Extreme Few, if any masonry structures remain standing. Bridges destroyed. Rails bent greatly.

XII. Cataclysmic

Total destruction – everything is destroyed. Lines of sight and level distorted. Objects thrown into the air. The ground moves in waves or ripples. Large amounts of rock move position. Landscape altered, or leveled by several meters. In some cases, even the routes of rivers are changed.

USGS  PAGER    PopulaNon  Exposed  to  Earthquake  Shaking  

Overall, the population in this region resides in structures that are highly vulnerable to earthquake shaking, though some resistant structures exist. The predominant vulnerable building types are unreinforced brick masonry and rubble/field stone masonry construction.  Red alert level for shaking-related fatalities. High casualties are probable and the disaster is likely widespread. Past events with this alert level have required a national or international level response.  Orange alert level for economic losses. Significant damage is likely. Estimated economic losses are less than 1% of GDP of Pakistan.  

Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC  

Images  courtesy  of  the  US  Geological  Survey  

Iran

Pakistan

Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC  

Earthquake and historic seismicity The earthquake epicentre (red star) is plotted on the map with regional seismicity since 1970. Although seismically active, this region has not experienced large damaging earthquakes in the recent history. In the past 40 years, only one significant event (M6.1 numbered 13 in map), which killed 6, has occurred within 200 km of the 2013 event, in June of 1990.

For full list of earthquakes numbered in the map, please go to http://earthquake.usgs.gov/earthquakes/eventpage/usb000jyiv#pager_historic

Tectonic interpretation

At a broad scale, the tectonics of this region are complex. The earthquake occurred as the result of oblique-strike-slip type motion at shallow crustal depths, above the Makran subduction zone. Here, there is a transition zone between northward subduction of the Arabia plate beneath the Eurasia plate and northward sliding of the India plate relative to the Eurasia plate.

Tectonic setting plotted using plate boundary data from the USGS.

Focal mechanism of the oblique-strike-slip

earthquake (Copyright USGS).

Diagram showing a oblique-strike slip-fault

Arabia plate

Eurasia plate

India plate

Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC  

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Seismogram  recordings  by  various  seismometers  across  the  UK  

S-waves

Time of earthquake

P-waves Surface waves

Seismic waves took just 10 minutes to travel through the Earth from the earthquake to the UK!

Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC  

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Find  out  more….  

•  BGS  (BriNsh  Geological  Survey)  –  seismology  and  earthquakes  –  frequently  asked  quesNons  hWp://www.earthquakes.bgs.ac.uk/educaNon/faqs/faq_index.html  

•  IRIS  (Incorporated  Research  InsNtuNons  for  Seismology)  –  learning  about  earthquakes  hWp://www.iris.edu/hq/programs/educaNon_and_outreach/students  

 •  UK  School  Seismology  Project  –  classroom  acNviNes,  videos  and  support  documents  

hWp://www.bgs.ac.uk/schoolseismology/home.html    •  USGS  (United  States  Geological  Survey)  –  FAQs,  glossary,  posters,  animaNons  

hWp://earthquake.usgs.gov/learn/  

•  USGS  summary  of  the  Pakistan  earthquakehWp://earthquake.usgs.gov/earthquakes/eventpage/usb000jyiv#summary  

Magnitude  7.7  AWARAN,  PAKISTAN  Tuesday,  24  September,  2013  at  11:29:48  UTC