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Cyclones

2016: "Vardah"

The Hindu, December 9, 2016

Sanjib Kumar Roy

Cyclonic storm Vardah brought normal life in a standstill in Andamans

Tourists still stranded as Havelock island remains unreachable

Havelock island remained unreachable for the second day on Thursday as the depression over the Andaman Sea intensified into cyclonic storm ‘Vardah’. Two passenger vessels of the Andaman Shipping Services, MV Rani Lakshmi and MV Kamorta, were sent to Havelock to evacuate nearly 1,100 tourists, but both the vessels had to return to Port Blair because of high waves in the sea.

Later, cargo vessel MV Badam was also sent to Havelock with supplies and medicines but had to return because of bad weather conditions. Sources said there were efforts to send Coast Guard vessels to Havelock to evacuate the tourists but bad weather put paid to this as well.

Impact

Locals extend help

Vessels of the Indian Navy, which had been sent to Havelock, were called back considering their safety at sea in the high waves.

Meanwhile, the local administration directed hotel and restaurant owners to help tourists by extending their bookings and by providing free food, whenever possible. While nearly 1,100 tourists are stranded at Havelock and 400 tourists continue to be stranded at Neil island, tourists stuck in the Port Blair area complained about poor coordination from the Tourism Department and lack of awareness about helpline centres for tourists.

They also complained of problems in extending bookings in hotels. In a video statement, Lieutenant Governor of Andaman & Nicobar Islands Jagdish Mukhi today claimed, “All tourists are safe. They could not be brought back to Port Blair only [upon] considering their safety.”

Landslides

Cyclone Vardah played havoc in many remote Islands, bringing normal life to a standstill. In the north and middle Andaman region, various islands like Diglipur, Rangat and Billyground witnessed a flood-like situation because of very heavy rainfall.

The movement of vehicles on the Andaman Trunk Road was disrupted in various places in middle and north Andaman due to flooding in low-lying areas. There were reports of landslides along the Andaman Trunk Road. The cyclone blew away roofs of several dozen houses and damaged crops in north and middle Andaman. Snapping of power cables has left many areas without power for more than two days.

The Deputy Commissioner of South Andaman, Udit Prakash Rai, said the administration would compensate those who had suffered loss because of the weather conditions.

The administration has suspended helicopter and shipping services. Some flights landed at Port Blair while many others were cancelled. The airport witnessed frayed tempers when SpiceJet cancelled its flight after passengers had boarded the aircraft.

Earthquakes

1881- 2010

Andaman and Nicobar Islands: Major Earthquakes, 1881- 2010, (M w > 6:5) That Occurred in and around the Andaman and Nicobar Islands
Sreevalsa Kolathayar
[1]

Andaman and Nicobar Islands: Major Earthquakes, 1881- 2010, (M w > 6:5) That Occurred in and around the Andaman and Nicobar Islands

PAST AND PRESENT SEISMICITY

Javed N. Malik,a… C.V.R. Murty,a… M.EERI, and Durgesh C. Rai,a… M.EERI Landscape Changes in the Andaman and Nicobar Islands (India) after the December 2004 Great Sumatra Earthquake and Indian Ocean Tsunami/ Earthquake Spectra, Volume 22, No. S3, pages S43–S66, June 2006; © 2006, Earthquake Engineering Research Institute

The region of the A&N islands has experienced several large-magnitude earthquakes in recent history. These were mainly thrust earthquakes, such as those in 1847, 1881, and 1941, which appear to have occurred in this region Rajendran et al. 2003, Bilham et al. 2005 . Recent global plate reconstruction data suggest that the northeast-moving Indian plate converges obliquely at 54 mm/yr with respect to the Eurasian plate DeMets et al.

The GPS observations between Bangalore and Port Blair the capital of the A&N islands suggest that the Indian plate is approaching the Burma plate at a rate of 15.3±3 mm/yr DeMets et al. 1994, Paul et al. 2001, Ortiz and Bilham 2003 . The GPS measurements suggest that great earthquakes with slip that is similar to the 2004 event cannot occur more frequently than once every 1,000 years; a shorter recurrence interval of 400 years has been calculated for the epicentral region, where convergence rates are higher Bilham et al. 2005 .

The seismicity of the A&N region is marked by several small-, moderate-, and largemagnitude earthquakes with M=4–8. Most of the earthquakes in this region show thrust and strike-slip faulting associated with oblique subduction of the Indian plate, along with some faulting associated with extensional stresses in the northern Andaman Sea Eguchi et al. 1979 . Several reports and other published data suggest that some of the events that occurred in the vicinity of the A&N island chain were as shallow as 10 km or less, and some were deeper than 250 km e.g., Mukhopadhyay 1984, Eguchi et al. 1979, Banghar 1987, Ortiz and Bilham 2003, Kayal et al. 2004, GSI 2003 . These earthquakes were mostly concentrated on the east and west of the islands along the trench and along the spreading center, respectively, barring some on the mainland. The shallow-tointermediate thrust earthquakes are the result of the Indian plate thrusting under the Burma microplate, along with several events showing a prominent strike-slip mechanism with some component of thrust inferred to be associated with oblique subduction between the Indian plate and the Burma plate Banghar 1987 . The normal faulting events associated with shallower depth are the result of the bending of the plate below the island arc Banghar 1987 . It has also been noted that the focal depth decreases as a function of latitude from south to north.

1941

George Pararas-Carayannis /EARTHQUAKE AND TSUNAMI OF JUNE 26, 1941 IN THE ANDAMAN SEA AND THE BAY OF BENGAL/ DRGeorgePC.com

Introduction

The earthquake of June 26, 1941 was one of the strongest in the Andaman & Nicobar Islands of India. The quake generated a tsunami in the Andaman Sea and the Bay of Bengal which was particularly destructive along the east coast of India.

Date and Origin Time: June 26, 1941, at 11:52:03 UTC (5)

Epicenter : 12.50 North, 92.57 East.

Earthquake Location: About 20.5 kms W of Flat Island, 23.6 kms WNW of Yadita (Middle Andaman Island Group), 96.7 kms NNW of Port Blair (South Andaman Islands), 617 kms SW of Yangon, Myanmar, and 834 kms NNW of Banda Aceh (Sumatra), Indonesia.

Earthquake Focal Depth - Shallow.

Magnitude: Originally the magnitude was estimated as Moment Magnitude, Mw 7.7M. However, based on the earthquake's long rupture, a Mw 8.1 was subsequently assigned to this event.

Aftershocks: In the hours following the major earthquake, a series of powerful aftershocks struck the region. Two magnitude 6.0 events struck within 24 hours of the main shock on June 27th, 1941. The first major afteshock occurred at 07:32:47 UTC and was followed by another at 08:32:19 UTC. There were 14 earthquakes of magnitude 6.0 - up to January 1942.

Felt Reports: Strong ground motions were felt throughout the Andaman and Nicobar Island groups. Highest intensities were experienced at Baratang Island, Shoal Bay Creek - north of Port Blair - and near Port Anson. Also, the quake was strongly felt over a large geographical region in the Bay of Bengal - particularly from the eastern coast of India (Coromandel ) to Colombo, Sri Lanka.

In Madras (Chennai), two strong tremors were felt, mostly by people in tall buildings. The first of these tremors lasted 2 seconds and the second 15 seconds. Two shocks were experienced also at Vishakhapatnam within a two-minute period. The earthquake was strongly felt in Calcutta ("Kolkata"), Chandernagar and Cuttack. At Cuttack the strong motions reportedly lasted for about four minutes. In Colombo, Sri Lanka, and at Syhlet, Bangladesh, the strong ground motions were felt for a few seconds.

Earthquake and Tsunami Damage and Death Toll: No detailed records are available from the Andaman and Nicobar islands - which were under Japanese occupation at that time. However, the death toll on the islands is estimated at over 3,000 and there is no specific record on the death toll and damage caused by the tsunami. Extensive eartquake damage occurred primarily on the Middle and South Andaman Islands. Most of the masonry structures in and around Port Blair were badly affected. The earthquake destroyed Cellular Jail - a three-story building - and all buildings on Ross Island, the administrative center of the British government.

2004 tsunami and After

Chandrima Banerjee, December 29, 2020: The Times of India

An earthquake with 10-minute-long waves is quite unusual. Many like it, in quick succession, even more so. But beneath the Andaman Sea near Nicobar, the 2004 earthquake and tsunami has set off a series of intermittent earthquake swarms that also indicate simmering volcanic activity. Scientists at the CSIR-National Institute of Oceanography in Goa on the research ship RV Sindhu Sankalp conducted a passive ocean bottom seismometer experiment for the first time in Indian waters.

They found 141 high-frequency earthquakes and swarms (bursts of quakes with a short period of time, ranging from hours to days) in areas where three faults — the Andaman Nicobar Fault, the West Andaman Fault and strands of the Great Sumatra Fault — meet.

Major swarms had occurred in the off Nicobar region in the Andaman Sea over five different periods — in January 2005, March 2014, October 2014, November 2015 and March 2019 — their study, published in Nature’s Scientific Reports this month, said.

They were really long. “The March 2014 swarm, for instance, had lasted 48 hours,” lead author Aswini KK told TOI. The swarm in January 2005 was the strongest ever recorded globally. Some earthquakes in 2014 had long period signals, like the 600-second signal they got. “This is rare and suggests the origin of the seismic waves is deep seated, located at a depth in the subsurface, about 30km below the seafloor,” corresponding author Kamesh Raju said. “At that depth, we expect magma at work.”

So while the December 2004 “tsunamigenic megathrust earthquake” itself was a reason, the active volcanism in the area has also been causing some shifts.

Does it mean an eruption might be in the offing? “The studies over the submarine volcanic chain that extends from Barren Island in the north to the onshore volcanoes of Sumatra would provide insights to answer the above question,” Raju said.

2004: Further details

C.V.R. Murty,a… M.EERI, Durgesh C. Rai,a… M.EERI, Sudhir K. Jain,a… M.EERI, Hemant B. Kaushik,a… Goutam Mondal,a… and Suresh R. Dasha/ Performance of Structures in the Andaman and Nicobar Islands (India) during the December 2004 Great Sumatra Earthquake and Indian Ocean Tsunami/ Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India/ Earthquake Spectra, Volume 22, No. S3, pages S321–S354, June 2006; © 2006, Earthquake Engineering Research Institute/ researchgate.net

The 26 December 2004 earthquake occurred along the subduction plate boundary between the Indian plate and the Burma micro plate of the Eurasian plate. Because of the seismic activity in the region, the Indian seismic zone map Figure 2 has placed the A&N islands in seismic zone V, the most severe one in the country. The location of the main shock was 200 km SSE of the nearest island Great Nicobar Island, about 1,000 km SSE from Port Blair, and about 1,800 km SE of Chennai formerly known as Madras. The main shock and aftershocks suggest that the rupture extended over about 1,300 km of the Sunda and Andaman arc USGS 2005. The large amount of energy released during this event caused high-intensity ground shaking at several locations along the land masses adjoining this arc. However, a preliminary estimate of the maximum intensity of shaking on the MSK scale sustained in India is only about VII along the A&N islands and about V along the east coast of mainland India. The digital strongmotion instrument installed at Port Blair by the India Meteorological Department failed to record the main event. The intensity of ground shaking in Port Blair was placed at VI–VII on the MSK scale Jain et al. 2005. For shaking intensity VII, the average peak ground acceleration is generally about 0.1 g. Analysis of a collapsed RC bicycle and motor scooter shelter also indicates that the peak ground acceleration in Port Blair during the earthquake was about 0.1 g Kaushik and Jain 2006.

The distribution of tsunami-induced damage along the A&N islands followed the general trend of more damage in the islands closer to the epicenter and less damage in those farther away. Persons interviewed at Port Blair recall that the water receded before the first wave, and the third wave came with the greatest height and caused maximum devastation. However, persons at locations far south of Port Blair, namely at Hut Bay, Malacca, and Campbell Bay, mention that the water level rose by about 1–2 m from the normal sea level and remained there before the giant wave lashed the entire built environment. Eyewitnesses recall that the tallest of the giant waves was about 5 m high at Campbell Bay in Great Nicobar Island, about 8 m at Malacca in Car Nicobar Island and at Hut Bay in Little Andaman Island, and about 4.5 m at Port Blair in South Andaman Island; these wave heights were also corroborated by field measurements by various agencies DST 2005 Figure 3. The partial shielding of the coastline at Campbell Bay and significant shielding of Port Blair and Campbell Bay by the steep mountainous outcrops from the direct tsunami waves originating from Sumatra may have contributed to the reduced wave heights at these locations. However, the open terrain along the eastern coast of the islands at Malacca and Hut Bay is seen as a reason for the large height of the tsunami waves.

2021

February 15

4.1-Magnitude Earthquake Strikes Andaman And Nicobar Island

India News | NDTV News Desk | Monday February 15, 2021

An earthquake of magnitude 4.1 was reported near Portblair in Andaman and Nicobar island on Monday evening, according to India's National Center for Seismolog

April 22

4.3 Magnitude Earthquake Hits Andaman And Nicobar

India News | NDTV News Desk | Thursday April 22, 2021

An earthquake of magnitude 4.3 was reported near Portblair in Andaman and Nicobar island on Thursday morning, according to India's National Center for Seismology.

August 3

Magnitude 6.1 Earthquake Strikes Near Andaman and Nicobar Island

India News | Reuters | Tuesday August 3, 2021

An earthquake of magnitude 6.1 struck about 310 km (190 miles) south southeast of Port Blair in Andaman and Nicobar island, the European-Mediterranean Seismological Centre (EMSC) said on Tuesday.

September 25

Earthquake Of 5.2 Magnitude Strikes Andaman & Nicobar

India News | Asian News International | Saturday September 25, 2021

Andaman and Nicobar Earthquake: An earthquake of magnitude 5.2 on the Richter scale struck near Campbell Bay in Andaman and Nicobar Islands on Friday night, as per the National Centre for Seismology (NCS).

October 27

4.0 Magnitude Earthquake Hits Andaman And Nicobar Islands

India News | NDTV News Desk | Wednesday October 27, 2021

An earthquake of magnitude 4.0 was reported near Diglipur in Andaman and Nicobar island on Wednesday morning, according to India's National Center for Seismology.

November 8

4.3 Magnitude Earthquake Hits Andaman And Nicobar Islands

India News | Asian News International | Monday November 8, 2021

An earthquake of magnitude 4.3 jolted Southeast of Port Blair in the early hours of Monday, the National Center for Seismology (NCS) informed.

December 29

4.3 Magnitude Earthquake Strikes Andaman And Nicobar Islands

India News | Asian News International | Wednesday December 29, 2021

An earthquake of magnitude 4.3 on the Richter scale jolted the Southeast of Andoman and Nicobar Islands' Portblair in the early hours of Wednesday, said the National Center for Seismology (NCS).

2022

April 6

Earthquake Of Magnitude 4.4 Hits Andaman And Nicobar Islands

India News | NDTV News Desk | Wednesday April 6, 2022

An earthquake of magnitude 4.4 was reported near Campbell Bay in Andaman and Nicobar island on Wednesday evening, according to National Center for Seismology.

April 10

4.9 Magnitude Earthquake Hits Andaman And Nicobar Islands

India News | Asian News International | Sunday April 10, 2022

An earthquake with a magnitude of 4.9 on the Richter Scale, hit Campbell Bay in the Andaman and Nicobar Islands on Sunday morning, said the National Center for Seismology.

May 9

4.4 Magnitude Earthquake Hits Andaman and Nicobar's Campbell Bay

India News | Asian News International | Monday May 9, 2022

An earthquake of magnitude 4.4 on the Richter scale hit Campbell Bay, Andaman and Nicobar island on Monday, said the National Center for Seismology.

June 21

4.3 Magnitude Earthquake Hits Andaman And Nicobar Islands

India News | Asian News International | Tuesday June 21, 2022

An earthquake of magnitude 4.3 on the Richter scale occurred 183 km southwest of Port Blair in the Andaman and Nicobar islands, informed the National Center for Seismology (NCS) on Tuesday

2023

April 9

Earthquakes Of Magnitude 5.3, 4.1 Strike Nicobar Island

India News | Asian News International | Sunday April 9, 2023

A second earthquake of magnitude 5.3 on the Ritcher scale occurred at a depth of 10 km, Nicobar Island on Sunday, according to the National Center for Seismology (NCS).

ANI/ Two earthquakes of magniture 5.3 and 4.1 hit Nicobar Island/ April 09, 2023/ The Hindu

The earthquake occurred at around 2.59 p.m., according to the National Centre for Seismology/ A second earthquake of magnitude 5.3 on the Ritcher scale occurred at a depth of 10 km, Nicobar Island on April 9, according to the National Center for Seismology (NCS).

The earthquake occurred at around 4:01 pm.

“Earthquake of Magnitude:5.3, Occurred on 09-04-2023, 16:01:21 IST, Lat: 9.01 & Long: 94.03, Depth: 10 Km, Location: Nicobar Islands, for more information Download the BhooKamp App,” tweeted NCS.

A few hours ago, an earthquake of magnitude 4.1 on the Ritcher scale occurred at a depth of 10 km, Nicobar Island. The earthquake occurred at around 2.59 pm.

April 13

4.4 Magnitude Earthquake Hits Andaman And Nicobar Islands

India News | Asian News International | Thursday April 13, 2023

An earthquake of magnitude 4.4 on the Richter Scale struck Campbell Bay in Andaman and Nicobar Islands on Thursday, informed National Centre for Seismology (NCS).

The distribution of earthquake events

The Andaman and Nicobar Islands: Distribution of earthquake events
Sreevalsa Kolathayar
[2]

The Andaman and Nicobar Islands: Distribution of earthquake events

Tsunami: 2004

Briefly

Andaman and Nicobar Islands Tsunami 2004
Suresh R Dash [3]

The Times of India

Dec 31 2014

Nicobar islands: some facts

Shamsher Bahadur Singh Deol

With most settlements located around jetties, the waves left the islands devastated. The coconut was the only source of food and water to those stranded. It was the self-belief of the indigenous people that enabled their survival and recovery

Before the tsunami of 2004, Nicobar islands had a population of 50,000, with almost all Nicobari tribals bearing allegiance to the Church of North India. For this sparsely populated area, the 3,500 lives lost in the tsunami amounted to 7% of the population. In 2004, I was posted as inspector general of police of the Andaman and Nicobar Islands. The epicentre was only 150km from Indira Point and the intensity of the earthquake was 9.1 on the Richter Scale; compare that to the Latur quake, which registered at a mere 6.4. The Richter Scale is not linear but exponential, the intensity multiplying 33 times for readings between 8 and 9, and quakes cause disturbances in the ocean that can reach a speed of up to 450km an hour. On the surface of the water, there is barely a ripple, 20 cm to 70 cm high, imperceptible to boats and fishermen at sea, but its awesome power erupts on barriers it encounters.

An unhealthy dose of what is termed as the `Island Psyche' inflicts the inhabitants of the Andamans.This is a combination of isolation, hopelessness, uncertainty and boredom. Throw in depression, mental illness and alcoholism and the psyche becomes a debilitation.

This psyche is what contributed to the concentration of people and buildings around the jetty of each island. At least periodically, this enabled the inhabitants to feel connected to the outside world, if only to Port Blair, to see who was coming or leaving on the erratic steamer service, to see if vegetables, cooking gas or milk powder was now available. Constructed around the jetty were the generator plants, water supply systems, schools, dispensaries, revenue offices, police stations, markets, banks. It was as `downtown' as it could get. In less than 20 seconds, the third wave of the tsunami wiped out all of it, along with thousands of people.

Along with the disappearance of police weaponry, wireless equipment, revenue records and vehicles, survivors were left without medicines, educational certificates, driving licences, land titles, kitchen utensils, spectacles, and other necessities too numerous to list. It was as if life had to begin anew.

The tsunami stripped the islands off these laboriously-built jetties, boats, communication links, intraisland roads and public services.Four thousand hectares of land was permanently submerged and some islands tilted from one side to the other. One of the islands, Trinkat, is today split into three separate islands.

Only around 300 rotting and bloated bodies were located in the 10 days after the event. We were required to photograph each of them but this formality had to be abandoned as no facial features were discernible. Only one accurate identification was achieved -that of a policeman in uniform, complete with name tag. To prevent epidemics, the police had to carry out cremations on the spot. A battered vehicle was located, the petrol siphoned off and sprinkled on the body, which was then covered with plastic chairs, pieces of cloth and dry wood before a fire was ignited.

In the three non-tribal islands, Campbell Bay, Kachal and Hut Bay, we were vociferously accosted with impossible demands, hostile sloganshouting and breast-beating. Even at Port Blair on December 26, I had to unsheath my revolver to control strident, almost violent tourists from the mainland who had surrounded the car of the Lieutenant Governor. To blame God or nature for the tsunami gives us nothing to rail at; we want a personification of our oppressor to vent our hate upon.

In sharp contrast, the Nicobarese were, without exception, dignified and disciplined. When we first visited their village, the survivors would be sitting neatly in rows on the ground. Women would cry with muted sobs, but no man would break down. The captain of the village was the only person to speak on their behalf, handing over a list of the two or three dead and the more than 200 missing. Nicobarese bestow names on their children with complete freedom. The list of the unfortunates included Alexander the Great, Sehwag, Cassius Clay, Ravi Shastri, Cleopatra, Vivian Richards, Josephine, Maradona, Sachin Tendulkar, Pele and Napoleon Bonaparte. So many dreams shattered.

Not used to dealing with money, they were bewildered by the vast amounts of compensation given to them. Upscale cars and motorcycles were purchased without consideration of maintenance and fuel costs. Money was loaned to friends, donated to clan members and invested with deceitful merchants. In the tribal areas where alcohol is forbidden by law, a bottle of rum was being sold for Rs2,000. Like the tsunami waves, the money came and went.

The media showed a dogged interest in only one aspect -the casualty figures. On the fifth day I went out on a limb to say that according to what I had seen and from reports received, approximately 5,000 citizens were dead, missing or injured. The home ministry, right up to the very top, was livid! Who did I think I was? On what basis was I giving out such wild and exaggerated figures? How many bodies had the police located? The answer at that stage was seven. I was therefore to retract my statement forthwith and correctly state that only seven persons had died and report compliance.

By this time, I was also livid. Who else but the inspector general of the Andaman and Nicobar police was most qualified to assess the numbers? I suggested that the ministry should overrule me and announce their own estimates. That was the end of that. Eventually the government started to pay some attention to our islands.

However much the government lauded its own relief efforts subsequently , it is the humble coconut that supplied food and water to those stranded till help could reach them. More crucially the self-reliance, and the self-belief, of the Nicobari people was the greatest factor in their survival and recovery.

See also

Andaman And Nicobar Islands

Andaman And Nicobar Islands: Fauna

Andaman And Nicobar Islands: Flora

Andaman And Nicobar Islands: Natural calamities

Andaman and Nicobar Islands: Parliamentary elections

Andaman and Nicobar Islands: Tribes

Census India 1931: The Population Problem in Andaman and Nicobar Islands