Bhutan Bhutan, officially the Kingdom of Bhutan, is a landlocked country in South Asia, in the Eastern Himalayas between China to the north and northwest and India to the south and southeast. With a population of over 727,145 and a territory of , ...

was struck by a major earthquake on 4 May 1714. It had an estimated magnitude of about 8.1 and caused shaking that reached IX (''Violent'') on the

Modified Mercalli intensity scale The Modified Mercalli intensity scale (MM, MMI, or MCS) measures the effects of an earthquake at a given location. This is in contrast with the seismic magnitude usually reported for an earthquake. Magnitude scales measure the inherent force or ...

. It is thought to have been caused by rupture of the Bhutan part of the

Main Frontal Thrust The Main Frontal Thrust (MFT), also known as the Himalayan Frontal Thrust (HFT), is a geological fault in the Himalayas that defines the boundary between the Himalayan foothills and Indo-Gangetic Plain. The fault is well expressed on the surf ...

. Damage was reported from west central Bhutan and northeast India. The earthquake resulted in "many fatalities".

Tectonic setting

Bhutan lies across the southern margin of the Himalayas. This mountain belt, and the

Tibetan Plateau The Tibetan Plateau, also known as the Qinghai–Tibet Plateau or Qingzang Plateau, is a vast elevated plateau located at the intersection of Central Asia, Central, South Asia, South, and East Asia. Geographically, it is located to the north of H ...

that lies north of it, is the result of the ongoing

collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great for ...

of the

Indian Plate The Indian plate (or India plate) is or was 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 an ...

with the Eurasian Plate. The main

active Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * "Active" (song), a 2024 song by Asake and Travis Scott from Asake's album ''Lungu Boy'' * Active Records, a record label Ships * ''Active'' (ship), several com ...

structures on the margin are a series of major

thrust fault A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. I ...

s. The basal thrust is known as the

Main Himalayan Thrust The Main Himalayan Thrust (MHT) is a décollement under the Himalaya Range. This thrust fault follows a northwest-southeast strike, reminiscent of an arc, and gently dips about 10 degrees towards the north, beneath the region. It is the large ...

(MHT) which links directly northwards into the plate boundary and forms the

décollement Décollement () is a gliding plane between two rock masses, also known as a basal detachment fault. Décollements are a Deformation (geology), deformational structure, resulting in independent styles of deformation in the rocks above and below t ...

for the whole thrust system. The southernmost thrust that reaches the surface is the

(MFT), which joins with the MHT at depth. Other shallower thrusts also branch (splay) off the MHT, including the

Main Central Thrust The Main Central Thrust is a major geological fault where the Indian plate has pushed under the Eurasian plate along the Himalaya. The fault slopes down to the north and is exposed on the surface in a NW-SE direction (strike). It is a thrust fault ...

and the

Main Boundary Thrust The Main Boundary Thrust (MBT), also known as the Main Boundary Fault, is a discontinuous series of seismic faults in the Himalayas which form the structural boundary between the Outer Himalayas and Lower Himalayan Range. The MBT is itself part ...

. All of these thrusts are capable of producing large and damaging earthquakes. The

April 2015 Nepal earthquake The April 2015 Nepal earthquake (also known as the Gorkha earthquake) killed 8,962 people and injured 21,952 across the countries of Nepal, India, China and Bangladesh. It occurred at on Saturday 25 April 2015, with a magnitude of Moment magni ...

is the most recent such event, which ruptured the MHT.

Earthquake

Earlier work on this event gave the year as 1713, but the discovery of more records strongly suggested that the earthquake occurred in 1714. This is supported by records of the event in northeastern India, stating that it occurred shortly before the death of King Rudra Singh in August 1714. The magnitude and location of the earthquake have been estimated using seismic intensities taken from damage records in both Bhutan and India. Further information has come from

paleoseismological Paleoseismology is the study of ancient Earthquake, earthquakes using geologic evidence, such as geologic Sediment, sediments and Rock (geology), rocks. It is used to supplement Seismology, seismic monitoring to calculate seismic hazard. Paleose ...

investigations of trenches dug across the Main Frontal Thrust. Evidence for surface rupture during this earthquake has been found at three sites along the outcrop of the MFT in Bhutan. The largest observed displacement attributed to this event was about 11 m at a site near

Samdrup Jongkhar Samdrup Jongkhar (Dzongkha:བསམ་གྲུབ་ལྗོངས་མཁར་) is a town and seat of Samdrup Jongkhar District in Bhutan. The town is located at the south-eastern part of Bhutan and borders the Indian state of Assam ...

, close to the Bhutan-India border. The magnitude is estimated to lie in the range 7.6–8.6 . The length of the rupture along the mountain front is estimated to be a minimum of 175 km and probably as much as 290 km. Thirty

aftershock In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in Epicenter, the same area of the Mainshock, main shock, caused as the displaced Crust (geology), crust adjusts to the effects of the main shock. Large earthq ...

s were reported on the same day as the earthquake, with more occurring over the following month.

Damage

The effects of this earthquake were recorded in the writings of the Chief Abbot, Shakya Rinchen, who experienced the event as a four-year-old. Intensities have been estimated from his descriptions at three locations,

Wangdue Phodrang Wangdue Phodrang (, Dzongkha 'Wangdi Phodr'a) is a town and capital (dzongkhag thromde) of Wangdue Phodrang District in central Bhutan. It is located in Thedtsho Gewog. Khothang Rinchenling History The town shares its name with the Wangdue Ph ...

, the

Punakha valley Punakha () is the administrative centre of Punakha dzongkhag, one of the 20 districts of Bhutan. Punakha was the capital of Bhutan and the seat of government until 1955, when the capital was moved to Thimphu. It is about 72 km away from Thim ...

and the

Thimphu valley Thimphu (; ) is the capital city, capital and largest city of Bhutan. It is situated in the western central part of Bhutan, and the surrounding valley is one of Bhutan's ''dzongkhags'', the Thimphu District. The ancient capital city of Punakha ...

. The Gangteng Monastery in

Phobjikha Valley The Phobjikha Valley ཕོབ་སྦྱིས་ཁ spelled as Pho-sbis-kha, (the suffix ''kha'' is an element in many place-names in Bhutan and its use is generally optional both in colloquial speech and in literary forms) is a vast U-shaped v ...

was also severely damaged. There are records of damage reported from northeastern India at three locations,

Tingkhong Tingkhong is a town of Dibrugarh district of Assam state in northeast India. Administratively Tingkhong is located within Dibrugarh district and is today an important tea cultivation and oil exploration area of Assam. Tingkhong is approximately 8 ...

Charaideo Charaideo or Che-Rai-Doi (Literally: ''the shining city on the hills'' in Ahom language) is a historic town situated in Charaideo district, Assam, India. Charaideo was established by the first Ahom king Chao Lung Siu-Ka-Pha in the year 1253 ...

and

Garhgaon Gargaon ( Tai-Ahom:Tsé-hung;) is a historic city in Assam, India and served as the capital of the Ahom kingdom for many years. It was built by the Ahom king Suklenmung (Gargaiya Roja) in 1540. It lies 13 km east of present-day Sivasa ...

. The only description of the resulting death toll is "many fatalities".

References

{{Himalayan earthquakes 1710s earthquakes Earthquakes in Asia Natural disasters in Bhutan 1714 in Asia Megathrust earthquakes in India