Browsing by Author "Alam, E"

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    Records of tsunamis in the Indian Ocean with a particular focus on the northern end of the Bay of Bengal
    (International Union of Geodesy and Geophysics, 2021-07-03) Alam, E; Dominey-Howes, D; Goff, JG; Chagué-Goff, C
    The Indian Ocean was considered to have a low tsunami risk in comparison to the Pacific Ocean but the 2004 Indian Ocean tsunami has challenged that idea. Recently, debate has arisen regarding the potential tsunamigenic nature of the Northern Bay of Bengal region. To test this debate, we document historical tsunamis in the Indian Ocean region with a particular focus on the Northern Bay of Bengal (Latitude 15oS to 29oN and Longitude 70oE to 106oE) through detailed analysis of records contained within online global tsunami catalogues, regional tsunami databases, research papers, newspapers and so on. A total of 122 tsunamis are reported in the existing datasets. After completing a process of validity assessment, we recognised 29 definite tsunamis, 17 very probable tsunamis, 20 possible tsunamis, 30 doubtful tsunamis, 19 events that only caused a seiche or disturbance in an inland river and seven as erroneously reported events, which are cyclones or earthquakes. We record 13 reported tsunamis having occurred prior to 1800 AD and 109 tsunamis between 1800 AD and August 2010. Of the reported events, the tsunamis of 2 April 1762, 11 November 1842, 31 December 1881, 27 August 1883, 5 May 1930 and 24 December 2004 severely impacted the northern Bay of Bengal and adjoining regions. We encountered a number of challenges while recording data from the sourced documents, which include: incorrect and incomplete citations, difference in dates from different sources for the occurrence of the same event, contradictory descriptions of earthquakes, tsunamis and cyclones.
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    Tsunamis of the northeast Indian Ocean with a particular focus on the Bay of Bengal region - a synthesis and review
    (Elsevier Science BV, 2012-08-01) Alam, E; Dominey-Howes, D; Chagué-Goff, C; Goff, JR
    The 2004 Indian Ocean Tsunami (2004 IOT) challenged assumptions about the level of regional hazard. Significantly, there has been some debate about the hypothesis that the northern Bay of Bengal may be capable of generating large tsunamis similar to the 2004 IOT. To test this hypothesis, we documented historical and palaeotsunamis in the northeast Indian Ocean. Using multiple sources, we identified 135 purported tsunamis. After completing a process of validity assessment, we categorised 31 definite tsunamis, 27 probable tsunamis, 51 doubtful tsunamis and 20 events that only caused a seiche or disturbance in an inland river. Six of the purported events were identified as either cyclones or earthquakes without any associated tsunamis. Using the reported list of 135 events, we identified different tsunamigenic regions and explored the temporal distribution of past events, with the oldest event dated to around 38,000BC (although the dated material is most likely reworked and this was probably a Holocene event). The second oldest event dated to 3000-2000BC. Historical records indicate that only one definite tsunami, occurring in AD1762, was generated in the northern Bay of Bengal. We encountered a number of significant challenges in reviewing and analysing data contained within the documents and sources we consulted. Statistical analysis of tsunami data from AD1710 to AD2010 suggests that the occurrence of a tsunami affecting the coasts of Bangladesh and Myanmar is 0.99% in any given year, and 63% in a century. We recognise that this incomplete tsunami dataset limits the capacity to fully quantify the hazard. As such, we recommend further 'deep' archival research coupled with regional palaeotsunami studies to gain a more sophisticated understanding of the hazard. © 2012, Elsevier Ltd.