The 2013 Balochistan earthquakes took place in late September in southwestern
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
. The mainshock had a
moment magnitude
The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...
of 7.7 and a maximum
Mercalli intensity
The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...
of IX (''Violent''). At least 825 people were killed and hundreds more were injured. On 28 September, a M6.8 aftershock occurred to the north at a depth of , killing at least 22 people.
Tectonic setting
On a broad scale, the
tectonics
Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...
of southern and central Pakistan reflect a complex
plate
Plate may refer to:
Cooking
* Plate (dishware), a broad, mainly flat vessel commonly used to serve food
* Plates, tableware, dishes or dishware used for setting a table, serving food and dining
* Plate, the content of such a plate (for example: ...
boundary where the India plate slides northward relative to the Eurasia plate in the east, and the Arabia plate
subducts northward beneath the Eurasia plate in the
Makran
Makran ( fa, مكران), mentioned in some sources as Mecran and Mokrān, is the coastal region of Baluchistan. It is a semi-desert coastal strip in Balochistan, in Pakistan and Iran, along the coast of the Gulf of Oman. It extends westwards, ...
(western Pakistan). These motions typically result in north–south to northeast–southwest strike-slip motion at the latitude of the 24 September earthquake that is primarily accommodated on the
Chaman Fault
The Chaman Fault is a major, active geological fault in Pakistan and Afghanistan that runs for over 850 km. , with the earthquake potentially occurring on one of the southernmost strands of this
fault system. Further, more in-depth studies will be required to identify the precise fault associated with this event. Although
seismically active, this portion of the Eurasia plate boundary region has not experienced large damaging earthquakes in recent history. In the past 40 years, only one significant event has occurred within of this event, which was a M
w 6.1 earthquake in July 1990 that killed six people.
[
]
Earthquake
The United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
reported that the earthquake took place on Tuesday 24 September 2013 at 11:29:48 UTC. The depth was reported to be . The earthquake reportedly lasted about a minute, causing panic in cities of southern Pakistan such as Karachi
Karachi (; ur, ; ; ) is the most populous city in Pakistan and 12th most populous city in the world, with a population of over 20 million. It is situated at the southern tip of the country along the Arabian Sea coast. It is the former cap ...
and Hyderabad
Hyderabad ( ; , ) is the capital and largest city of the Indian state of Telangana and the ''de jure'' capital of Andhra Pradesh. It occupies on the Deccan Plateau along the banks of the Musi River (India), Musi River, in the northern part ...
.[
The earthquake in occurred as the result of oblique-]strike-slip
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
type motion at shallow crustal depths. The location and mechanism of the earthquake are consistent with rupture
Rupture may refer to:
General
* Rupture (engineering), a failure of tough ductile materials loaded in tension
Anatomy and medicine
* Abdominal hernia, formerly referred to as "a rupture"
* Achilles tendon rupture
* Rupture of membranes, a "wate ...
within the Eurasia plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
above the Makran Trench
The Makran Trench is the physiographic expression of a subduction zone along the northeastern margin of the Gulf of Oman adjacent to the southwestern coast of Balochistan of Pakistan and the southeastern coast of Iran. In this region the oce ...
subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...
zone. The event occurred within the transition zone between northward subduction of the Arabian plate
The Arabian Plate is a minor tectonic plate in the Northern and Eastern Hemispheres.
It is one of the three continental plates (along with the African and the Indian Plates) that have been moving northward in geological history and collidin ...
beneath the Eurasia plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
and northward collision of the India plate
The Indian Plate (or India Plate) is a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian Plate broke away from the other fragments of Gondwana , began mov ...
with the Eurasia plate.[
]
Damage
The earthquake killed at least 825 people and injured hundreds of others. The earthquake struck a sparsely populated region of Pakistan. Most homes and buildings in the region are constructed of mud bricks and collapsed during the earthquake and aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousand ...
s. An official in the Balochistan province claimed that 80 percent of the homes in the Awaran District
Awaran District ( Balochi and ur, ), is a district in the south of the Balochistan province of Pakistan. It was created as a separate district in November 1992; but previously it was a sub-division of Khuzdar District. The old name of Awaran w ...
had collapsed or were damaged. In the regional capital Quetta
Quetta (; ur, ; ; ps, کوټه) is the tenth List of cities in Pakistan by population, most populous city in Pakistan with a population of over 1.1 million. It is situated in Geography of Pakistan, south-west of the country close to the ...
, some areas appeared to be badly damaged.[ Officials from the Balochistan government estimated that at least 21,000 houses had been completely destroyed by the tremor, while some areas remained beyond the reach of rescue services 48 hours after the initial quake.]
PAGER
A pager (also known as a beeper or bleeper) is a wireless telecommunications device that receives and displays alphanumeric or voice messages. One-way pagers can only receive messages, while response pagers and two-way pagers can also acknow ...
impact estimates from the United States Geological Survey included a red alert level for initial shaking-related fatalities (35% chance of 1,000–10,000 fatalities, 27% chance of 10,000–100,000 fatalities) and an orange alert level for economic impact (35% chance of US$100 million–$1 billion, 26% chance of US$1–10 billion).
The earthquake was felt in major cities across Pakistan, including Karachi, Hyderabad, Rawalpindi
Rawalpindi ( or ; Urdu, ) is a city in the Punjab province of Pakistan. It is the fourth largest city in Pakistan after Karachi, Lahore and Faisalabad, and third largest in Punjab after Lahore and Faisalabad. Rawalpindi is next to Pakistan's ...
/Islamabad
Islamabad (; ur, , ) is the capital city of Pakistan. It is the country's ninth-most populous city, with a population of over 1.2 million people, and is federally administered by the Pakistani government as part of the Islamabad Capital T ...
, Larkana
Larkana ( ur, , translit=lāṛkāna; sd, لاڙڪاڻو, translit=lāṛkāṇo) is a city located in the Sindh province of Pakistan. It is the 15th largest city of Pakistan by population. It is home to the Indus Valley civilization site Moh ...
, and Lahore
Lahore ( ; pnb, ; ur, ) is the second most populous city in Pakistan after Karachi and 26th most populous city in the world, with a population of over 13 million. It is the capital of the province of Punjab where it is the largest city. ...
. The quake was also felt in Delhi
Delhi, officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, primarily its western or right bank, Delhi shares borders w ...
, India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, where some buildings shook, and Muscat
Muscat ( ar, مَسْقَط, ) is the capital and most populated city in Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is s ...
, Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of t ...
— from the epicenter—where mild tremors shook tables and cabinets. The earthquake shook in the parts of UAE
The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia (The Middle East). It is located at th ...
, Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
, Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
, Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
and Qatar
Qatar (, ; ar, قطر, Qaṭar ; local vernacular pronunciation: ), officially the State of Qatar,) is a country in Western Asia. It occupies the Qatar Peninsula on the northeastern coast of the Arabian Peninsula in the Middle East; it sh ...
. The earthquake also shook Saravan, Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
without causing any damage or casualties. There were also minor tremors and aftershocks in the United Arab Emirates
The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia (The Middle East). It is located at th ...
.
Ground effects
The earthquake was apparently powerful enough to raise a small island, later dubbed Zalzala Jazeera
Zalzala Koh (, ''Earthquake Mountain'') or Zalzala Jazeera (''Earthquake Island'') was a small island off the coast of the port city of Gwadar in Balochistan province of Pakistan which appeared on 24 September 2013 following an earthquake. As pre ...
, meaning "quake island", in the Arabian Sea
The Arabian Sea ( ar, اَلْبَحرْ ٱلْعَرَبِيُّ, Al-Bahr al-ˁArabī) is a region of the northern Indian Ocean bounded on the north by Pakistan, Iran and the Gulf of Oman, on the west by the Gulf of Aden, Guardafui Channel ...
, variously reported as being to off the shore of Gwadar
Gwadar ( Balochi/ ur, ) is a port city with located on the southwestern coast of Balochistan, Pakistan. The city is located on the shores of the Arabian Sea opposite Oman. Gwadar is the 100th largest city of Pakistan, according to the 2017 ...
.[ The island is partially composed of rock, but mostly consists of mud and sand. The oval-shaped island was high and about long according to local people that visited the island the day after it appeared. They noticed a smell of gas and managed to ignite it, later extinguishing it with difficulty.][
The island is believed to be the result of a ]mud volcano
A mud volcano or mud dome is a landform created by the eruption of mud or slurries, water and gases. Several geological processes may cause the formation of mud volcanoes. Mud volcanoes are not true igneous volcanoes as they do not produce lava ...
. In the region, deposits of frozen gas hydrates
Clathrate hydrates, or gas hydrates, clathrates, hydrates, etc., are crystalline water-based solids physically resembling ice, in which small non-polar molecules (typically gases) or polar molecules with large hydrophobic moieties are trapped i ...
—which have a large methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...
content—exist beneath of compressed sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
. After such a large earthquake, the gas hydrates converted from frozen to gaseous form through the heat of friction and either raised the overlaying sediment enough to create fissures through which it escaped or rose through fissures resulting from the earthquake itself. Another possible contributing factor in the island's creation was the liquefaction
In materials science, liquefaction is a process that generates a liquid from a solid or a gas or that generates a non-liquid phase which behaves in accordance with fluid dynamics.
It occurs both naturally and artificially. As an example of the ...
of the seabed, which allowed finer, loosely packed sediments to become liquid-like and squeeze up through fissures in overlying compressed sediment. Locals who ventured to the island shortly after it formed heard a hissing noise at one end and started a fire which was difficult to extinguish. There are several mud volcanoes inland near Zalzala Jazeera and they are common in the vicinity of subducting plate boundaries; in fact, similar islands have appeared in the same region following earthquakes in 1945, 1999, 2001, and 2010. Because of its composition of softer sediments, the sea was predicted to erode the island completely within a few months.[ By the end of 2016, the island had completely disappeared.]
Tsunami
Despite its inland epicentre, the earthquake generated a tsunami with a maximum height of in eastern Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of t ...
.
Aftershocks
* 5.8 earthquake at occurred at 11:36:27 UTC (16:36:27 PKT) on 24 September at a depth of .
* 5.6 earthquake at occurred at 13:01:39 UTC (18:01:39 PKT) on 24 September at a depth of .
* 5.5 earthquake at occurred at 17:20:13 UTC (22:20:13 PKT) on 24 September at a depth of .
* 6.8 earthquake at occurred at 07:34:06 UTC (12:34:06 PKT) on 28 September at a depth of .
Aftermath
On 26 September, two days after the disaster, two rockets were fired at a helicopter carrying Maj. Gen. Muhammad Saeed Aleem, the National Disaster Management Authority chairman, as well as other officials and members of the media. Government sources blamed Balochi separatists, who are very active in the Awaran area.
See also
*List of earthquakes in 2013
This is a list of earthquakes in 2013. Only earthquakes of magnitude 6 or above are included, unless they result in damage and/or casualties, or are notable for some other reason. All dates are listed according to UTC time. This year was quite ...
*List of earthquakes in Pakistan
Pakistan is one of the most seismically active countries in the world, being crossed by several major faults. As a result, earthquakes in Pakistan occur often and are destructive.
Geology
Pakistan geologically overlaps both the Eurasian and I ...
References
Sources
*
*
External links
M7.7 - 61km NNE of Awaran, Pakistan
– United States Geological Survey.
Pakistan quake island off Gwadar 'emits flammable gas'
– BBC News
*
*
{{Earthquakes in Pakistan
2013 earthquakes
2013 disasters in Pakistan
Earthquakes in Pakistan
History of Balochistan, Pakistan (1947–present)
2
September 2013 events in Pakistan
Earthquake clusters, swarms, and sequences