Saturday, November 28, 2020

Documented tsunamis in the last five 500 years (Tsunami History Pt. 2)

Dhanesh Wisumperuma


The Island, 15.02.2005

http://archive.island.lk/2005/02/15/features5.html

Part 1 of the article - Tsunami during King Kelanitissa’s Reign


After the tsunami during King Kelanitissa's reign, described in our chronicles, there have been few reported natural disasters in our history. There have been a few earthquakes referred to as polo kampitha vima, and bhumikampa in Sinhalese. There have even been a few that are connected with important religious occasions in history. However, there is no mention of deluging of the sea, inundation of land or tidal waves. On the other hand, we cannot assume that there were no tsunamis, as there may have been unrecorded tsunamis. We must remember that the importance of recording such events was not among the highest priorities of chronicle writers.

Apart from the chronicles, earthquakes have been documented in western writing on Sri Lanka since the arrival of the Portuguese in the 16th century. However, most of them are on earthquakes and I am yet unable to trace writing referring to a tidal wave or tsunami.



1615 and 1627

Some newspaper articles mentioned that there had been a tsunami in 1615. However, it was an earthquake only and there was no tsunami associated with it. Reports describing this event are scarce and the most interesting is a Portuguese four-page pamphlet, titled "True Description of the Terrible Earthquake" with a strong religious background, published in Lisbon in 1616. In this, the 1615 incident is clearly depicted as an earthquake.

This particular earthquake struck the island on 14th April 1615. Before occurred, a 'fearful comet' with three tails was seen in the sky from March 7th, frightening people. According to this pamphlet, several deceases and other calamities occurred, spread rapidly resulting in death of humans, animals and fish. Eventually on April 14 at 7 o'clock in the evening, the earthquake took place and the shocks lasted until the next morning. The description of this terrible event provides details about what happened on that sorrowful night. Apart from the quake, there was lightening which would have caused fires too. According to the above-mentioned document, at least 2,000 people died due to the earthquake and lightning. About 200 houses were destroyed. It also describes damage to a stone bridge, bastion etc.

This seems to be an earthquake that caused immense damage to the island. However the pamphlet never mentions any tidal waves or other strong sea action, hence we cannot conclude that there was a tsunami based on this document.

There is a mention of high tides that deluged Jaffna on 20th February 1627 in De Queyroz's "Temporal and Spiritual Conquest of Ceylon". However, according to this description, these tides seems to be associated with a severe storm. There is no mention about an earthquake or any vibrations. Hence there is no evidence to assume that was a tsunami.

Tsunamis are ocean waves produced by movements of the ocean floor associated with earthquakes, volcanic eruptions or landslides. The word tsunami, which means 'harbour waves' came into wide use after it was officially approved for general use during an international scientific conference in 1963.

Other Earthquakes

Apart from the above, there were several minor earthquakes that were sensed in Sri Lanka. During the British occupation of the island, these earthquakes had been reported in newspapers and in the government gazette. Two of these earthquakes occurred in the early 19th century.

The first earthquake, recorded after the British captured the low country of the island, struck Batticaloa area on 13th July 1814. That was described in an extract of a private letter published in The Ceylon government gazette. In that eyewitness's report, he states that he was unable to record the effect on water bodies including sea and lagoon.

A second earthquake was sensed in Colombo, Trincomalee, Jaffna and Batticaloa on 9th February 1823. It had been strongest in Batticaloa, although no material damage is on report. According to available details, there have been no tsunamis associated with these earthquakes.

There are at least six major tsunamis that occurred between the 16th - 19th centuries as identified in this region by scientists. These tsunamis were recorded in 1524, 1762, 1819, 1847, 1881 and 1883 respectively. According to available details, the tsunamis in 1881 and 1883 were recorded from Sri Lanka. The main objective of this article is to discuss the tsunami that occurred following an earthquake in 1881 and volcanic eruptions in1883.



Tsunami in 1881


This tsunami was the result of a submarine earthquake beneath the Andaman Islands and struck on the eastern coast of Sri Lanka in the morning on 31st December 1881. Both the earthquake and tsunami were detected in Sri Lanka. One of the descriptions available is in the report on the Trincomalee district published in the Administrative Reports of 1881. Under a paragraph named "Notable Occurrences" it is mentioned that the earthquake that had been sensed in several parts of the district and the town resulted in minor damages to the rest house in Kantalai. A tsunami followed this quake. In the above description, it is mentioned that the water in the inner harbour rose and fell several times, receding from the shore in front of the Kachcheri to some distance and quickly flowing in again to the shore.' This was also noticed at Gun Wharf Pier and recorded by an officer of the Royal Engineers Department when the work at the pier was underway.

This tsunami was reported from Batticaloa area too and tide gauge stations of India around the Bay of Bengal.

The well-documented tsunami in 1883




The series of volcanic eruptions popularly known as the Krakatau (Krakatoa) eruption starting on 26th August 1883 was one of the largest volcanic eruptions in history. Thousands died and a part of the island of Krakatau, situated in the Sunda Strait between the Java and Sumatra islands was submerged. These eruptions created a tsunami that travelled across the Indian Ocean. Although this was a land eruption, the tsunami was created by the submarine explosions, collapsing of the calderas and the magma flow entering the sea. The tsunami travelled a long distance and was recorded in Ceylon, India etc.

After the recent tsunami in South Asia, several persons had mentioned that there are no reliable records in Sri Lanka for the tsunami of 1883. They may be referring to the newspaper reports. However, there is one dependable and somewhat scientific report, which is also an official report on the tsunami. This report has recorded tsunami conditions from at least 15 places along the coast of the island, the damage caused and at least one death.



Newspaper Reports


Although newspaper reports of this tsunami were discussed in some media, I would like to take a quick look at what these reports are saying. We have reports from newspapers where we can observe that the people had some sort of knowledge of what was happening. Although the word used for this tsunami was tidal waves, it was a tsunami.

The Times of Ceylon on 28th August 1883 describes the tidal waves off the coast. This description is mainly about what happened at the Colombo harbour, and describes it as a sudden and remarkable disturbance of the water. According to this description waves from seaward, round the head of the breakwater, passed quite up to the Jetties and the Custom House premises, where a rise of six feet was distinctly noted." This describes the receding of waves, which took place soon after. However the harbour authorities were judging the cause for this to some extent, stating that this can be caused "only by an earthquake below the water of the ocean some short distance off the coast.

The tusnami in the Galle harbour is described in the same newspaper on the 29th and 30th.The reports said it was caused by the Krakatoa eruption.

In the Observer newspaper, it was described the rise and fall of water at Colombo harbour. In this report, it is clearly stated by the harbour authorities that this may be a result of an underwater volcanic eruption.

This tsunami was even recorded in the Sinhala press, but based mainly on the reports of English papers. The Sarasavi Sandaresa newspaper gives a description about the tsunami under the title "Muhude Apuru Diya Hindeemak" (Remarkable receding of the sea) on 31st August 1883. A lengthy description in the Sarasavi Sandaresa, published on September 7th, states that the water receding from the Colombo harbour was about 8-10 feet. Another important event it reports is that the people went to the sea and collected things that were unearthed when the sea receded. People in Galle were able to catch fish when the water receded. It is stated that there were reports of tidal waves from Panadura, Kalutara, Galle, Batticaloa and some other places.

A government report of tsunami


However, the most important report is the government report on the tsunami. J. Stoddart, acting surveyor-general of Ceylon was the compiler of the report. After the initial reports of the tidal waves and volcanic eruption, he had issued circulars to government agents and other officers stationed along the coast requesting more information such as details of the rise and fall of the sea, shocks of the earthquake, sounds etc. He was able to compile a report from the details he obtained from them. Stoddart submitted it to the colonial secretary in March 1884. This particular report was published as sessional paper No. IV of 1884. This is the best source for the tsunami in 1884.

The table gives details of the tsunami impact of 1883 and is prepared from the data published in the above mentioned sessional paper. The times, wave height and the number of tidal (tsunami) waves were given as ranges because as I think, the people had to recall the events later and the lack of tidal gauges in certain places.

In many of the above-mentioned places sound from the eruptions were heard since the night of the August 26th and mainly in the morning of the 27th. Most people said the noise had been similar to distant thunder or canon. (The third eruption of the total of 4 major eruptions is said to be the largest sound ever heard by humanity and was recorded 4,800 km away!)

Rising of water is mentioned in some places including Trincomalee and Batticaloa as it rose with some force. In Navalaru and Panama saltwater intrusion was detected a long way inland, 1.5 miles in the former. This gives us an idea of the power of the waves and the distance they penetrated.

The damage due to the tsunami is considerably low as the waves were not so powerful. However, the waves in some places were considerably higher than the highest tide. For example in Hambantota, it was estimated that water rose up to 12 feet. I have summarized the details of the damage in the table. The woman who died due to injuries suffered at Arugam Bay was the only person to die in this tsunami.

According to the reports, nothing has been reported in the area between Mannar and Jaffna apart from the sound of the eruption. (A paper published in 2003 in the journal called Natural Hazards and Earth System Sciences on the tsunami propagation of the1883 volcanic eruption mentions the impact on the Dutch Bay in Kalpitiya as Negombo, probably due to a mistake.)

What are the lessons we can learn?


These tsunami documentations and details were prepared more than a century ago. They should have been used for a better understanding of tsunamis in Sri Lanka. For instance, a closer look at the times impacts was first observed may be important. According to the available data, it can be noticed that tsunami waves first struck the eastern coast, the south and then the west. However, records of first strikes in the eastern coast are not as clear as in Batticaloa.

Unfortunately, this has not happened to a satisfactory extent to at least give the general public an understanding of natural disasters like tsunamis. Historical evidence of the tsunamis will definitely be a strong foundation for such a programme.

We must accept one thing. Tsunamis are not new to us, That is the truth. We should have known about tsunamis and how to deal with them. We have not done this and thought we are safe from natural hazards. We know that it is not so. Therefore we have to face the reality and make use of this information in future.

No comments:

Post a Comment