Tide Gauge Observations of 2004–2007 Indian Ocean Tsunamis from Sri Lanka and Western Australia

2009 ◽  
Vol 166 (1-2) ◽  
pp. 233-258 ◽  
Author(s):  
Charitha B. Pattiaratchi ◽  
E. M. Sarath Wijeratne
Keyword(s):  
Sri Lanka ◽  
Indian Ocean ◽  
Western Australia ◽  
Tide Gauge

An update of proposed Sri Lanka warning system for east and west coast tsunamis

2019 ◽  
Vol 11 (2) ◽  
pp. 169-186
Author(s):  
Sanjeewa Wickramaratne ◽  
S. Chan Wirasinghe ◽  
Janaka Ruwanpura
Keyword(s):  
Sri Lanka ◽  
Indian Ocean ◽  
West Coast ◽  
Arrival Time ◽  
Service Providers ◽  
Tide Gauge ◽  
Content Type ◽  
Tsunami Detection ◽  
The Indian Ocean ◽  
Buoy Data

Purpose Based on the existing provisions/operations of tsunami warning in the Indian Ocean, authors observed that detection as well as arrival time estimations of regional tsunami service providers (RTSPs) could be improved. In particular, the detection mechanisms have been eccentrically focussed on Sunda and Makran tsunamis, although tsunamis from Carlsberg ridge and Chagos archipelago could generate devastating tsunamis for which inadequate provisions exist for detection and arrival time/wave height estimation. RTSPs resort to assess estimated arrival time/wave heights from a scenario-based, pre-simulated database. These estimations in terms of Sri Lanka have been found inconsistent. In addition, current warning mechanism poorly manages non-seismic tsunamis. Thus, the purpose of this study is to investigate these drawbacks and attempt to carve out a series of suggestions to improve them. Design/methodology/approach The work initiated with data retrieved from global earthquake and tsunami databases, followed by an estimation of probabilities of tsunamis in the Indian Ocean with particular emphasis on Carlsberg and Chagos tsunamis. Second, probabilities of tsunami detection in each sub-region have been estimated with the use of available tide gauge and tsunami buoy data. Third, the difficulties in tsunami detection in the Indian Ocean are critically assessed with case studies, followed by recommendations to improve the detection and warning. Findings Probabilistic estimates show that given the occurrence of a significant earthquake, both Makran and Carlsberg/Chagos regions possess higher probabilities to harbour a tsunami than the Sunda subduction zone. Meanwhile, reliability figures of tsunami buoys have been declined from 79-92 to 68-91 per cent over the past eight years. In addition, a Chagos tsunami is left to be detected by only one tide gauge prior to it reaching Sri Lankan coasts. Research limitations/implications The study uses an averaged tsunami speed of 882 km/h based on 2004 Asian tsunami. However, using exact bathymetric data, Tsunamis could be simulated to derive speeds and arrival times more accurately. Yet, such refinements do not change the main derivations and conclusions of this study. Practical implications Tsunami detection and warning in the Indian Ocean region have shown room for improvement, based on the inadequate detection levels for Carlesberg and Chagos tsunamis, and inconsistent warnings of regional tsunami service providers. The authors attempted to remedy these drawbacks by proposing a series of suggestions, including a deployment of a new tsunami buoy south of Maldives, revival of offline buoys, real-time tsunami simulations and a strategy to deal with landslide tsunamis, etc. Social implications Indian Ocean is prone to mega tsunamis as witnessed in 2004. However, more than 50 per cent of people in the Indian Ocean rim countries dwell near the coast. This is verified with deaths of 227,898 people in 14 countries during the 2004 tsunami event. Thus, it is of paramount importance that sufficient detection levels are maintained throughout the Indian Ocean without being overly biased towards Sunda tsunamis. With respect to Sri Lanka, Makran, Carlesberg or Chagos tsunamis could directly hit the most populated west coast and bring about far worse repercussions than a Sunda tsunami. Originality/value This is the first instance where the threats from Carlesberg and Chagos tsunamis to Sri Lanka are discussed, probabilities of tsunamis are quantified and their detection levels assessed. In addition, reliability levels of tsunami buoys and tide gauges in the Indian Ocean are recomputed after eight years to discover that there is a drop in reliability of the buoy data. The work also proposes a unique approach to handle inconsistencies in the bulletins of regional tsunami service providers, and to uphold and improve dwindling interest on tsunami buoys.

scholarly journals Analysis of Real GDP, Imports and Exports of Indian Ocean RIM Association Member Nations

2021 ◽  
Vol 58 (2) ◽  
pp. 68-100
Author(s):  
Manbir Singh, Dr. Jasdeep Kaur Dhami
Keyword(s):  
South Africa ◽  
Sri Lanka ◽  
Indian Ocean ◽  
Regional Cooperation ◽  
Islamic Republic ◽  
Association Member ◽  
Real Gdp ◽  
Time Period ◽  
The Indian Ocean

The Indian Ocean woven together by transmission of trade, commands the control of majority of the world’s cargo ships, one third of the worlds cargo traffic and two thirds of total world’s oil shipments. The main aim of this paper is to analyse Real GDP, Imports and Exports of Indian Ocean RIM Association Member Nations. Time period of the study is from 1980 to 2019.  Indian Ocean Rim Association for Regional Cooperation (IOR-ARC) contributes 11.7 per cent share in world exports, in case of member nations highest share is of Singapore 2.1 per cent  followed by India and UAE 1.7 per cent, Australia 1.5 per cent, Thailand and Malaysia 1.3 per cent. Indonesia, South Africa, Bangladesh, Oman, Iran, Islamic Republic of, Sri Lanka the share in world exports is less than 1 per cent.  

The Indian Ocean tsunami of December 26, 2004: observations in Sri Lanka and Thailand

2006 ◽  
Vol 42 (1) ◽  
pp. 105-124 ◽  
Author(s):  
T. Rossetto ◽  
N. Peiris ◽  
A. Pomonis ◽  
S. M. Wilkinson ◽  
D. Del Re ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Indian Ocean ◽  
Indian Ocean Tsunami ◽  
The Indian Ocean

Interannual Rainfall Extremes over Southwest Western Australia Linked to Indian Ocean Climate Variability

2006 ◽  
Vol 19 (10) ◽  
pp. 1948-1969 ◽  
Author(s):  
Matthew H. England ◽  
Caroline C. Ummenhofer ◽  
Agus Santoso
Keyword(s):  
Indian Ocean ◽  
Western Australia ◽  
Wind Field ◽  
Large Scale ◽  
Extreme Rainfall ◽  
Ekman Transport ◽  
Eastern Indian Ocean ◽  
Basin Scale ◽  
Rainfall Extremes ◽  
The Indian Ocean

Abstract Interannual rainfall extremes over southwest Western Australia (SWWA) are examined using observations, reanalysis data, and a long-term natural integration of the global coupled climate system. The authors reveal a characteristic dipole pattern of Indian Ocean sea surface temperature (SST) anomalies during extreme rainfall years, remarkably consistent between the reanalysis fields and the coupled climate model but different from most previous definitions of SST dipoles in the region. In particular, the dipole exhibits peak amplitudes in the eastern Indian Ocean adjacent to the west coast of Australia. During dry years, anomalously cool waters appear in the tropical/subtropical eastern Indian Ocean, adjacent to a region of unusually warm water in the subtropics off SWWA. This dipole of anomalous SST seesaws in sign between dry and wet years and appears to occur in phase with a large-scale reorganization of winds over the tropical/subtropical Indian Ocean. The wind field alters SST via anomalous Ekman transport in the tropical Indian Ocean and via anomalous air–sea heat fluxes in the subtropics. The winds also change the large-scale advection of moisture onto the SWWA coast. At the basin scale, the anomalous wind field can be interpreted as an acceleration (deceleration) of the Indian Ocean climatological mean anticyclone during dry (wet) years. In addition, dry (wet) years see a strengthening (weakening) and coinciding southward (northward) shift of the subpolar westerlies, which results in a similar southward (northward) shift of the rain-bearing fronts associated with the subpolar front. A link is also noted between extreme rainfall years and the Indian Ocean Dipole (IOD). Namely, in some years the IOD acts to reinforce the eastern tropical pole of SST described above, and to strengthen wind anomalies along the northern flank of the Indian Ocean anticyclone. In this manner, both tropical and extratropical processes in the Indian Ocean generate SST and wind anomalies off SWWA, which lead to moisture transport and rainfall extremes in the region. An analysis of the seasonal evolution of the climate extremes reveals a progressive amplification of anomalies in SST and atmospheric circulation toward a wintertime maximum, coinciding with the season of highest SWWA rainfall. The anomalies in SST can appear as early as the summertime months, however, which may have important implications for predictability of SWWA rainfall extremes.

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