Influence of geomorphology and bathymetry on the effects of the 2004 tsunami at Colachel, South India

Hentry, C.; Chandrasekar, N.; Saravanan, S.; Sahayam, J. Dajkumar

doi:10.1007/s10064-010-0303-1

Cited by 17 publications

(5 citation statements)

References 3 publications

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“…It is well known that a tsunami's behavior is dependent upon bathymetric features and coastal geometries (e.g., Matsuyama, 1999;Hentry et al, 2010;Yoon et al, 2014). When it approaches coastlines or seamounts, the wave shoaling leads to the rising up of the amplitude and slows down the tsunami as the water depth reduces.…”

Section: Bathymetric Gridsmentioning

confidence: 99%

The M_w 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

Roger

Pelletier

Duphil

et al. 2021

Nat. Hazards Earth Syst. Sci.

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Abstract. On 5 December 2018, a magnitude Mw 7.5 earthquake occurred southeast of Maré, an island of the Loyalty Islands archipelago, New Caledonia. This earthquake is located at the junction between the plunging Loyalty Ridge and the southern part of the Vanuatu Arc, in a tectonically complex and very active area regularly subjected to strong seismic crises and earthquakes higher than magnitude 7 and up to 8. Widely felt in New Caledonia, it was immediately followed by a tsunami warning, confirmed shortly after by a first wave arrival at the Loyalty Islands tide gauges (Maré and Lifou), and then along the east coast of Grande Terre of New Caledonia and in several islands of the Vanuatu Archipelago. Two solutions of the seafloor initial deformation are considered for tsunami generation modeling, one using a non-uniform finite-source model from USGS and the other being a uniform slip model built from the Global Centroid Moment Tensor (GCMT) solution, with the geological knowledge of the region and empirical laws establishing relationships between the moment magnitude and the fault plane geometry. Both tsunami generation and propagation are simulated using the Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM), an open-source modeling code solving the shallow-water equations on an unstructured grid allowing refinement in many critical areas. The results of numerical simulations are compared to tide gauge records, field observations and testimonials from 2018. Careful inspection of wave amplitude and wave energy maps for the two simulated scenarios shows clearly that the heterogeneous deformation model is inappropriate, while it raises the importance of the fault plane geometry and azimuth for tsunami amplitude and directivity. The arrival times, wave amplitude and polarities obtained with the uniform slip model are globally coherent, especially in far-field locations (Hienghène, Poindimié and Port Vila). Due to interactions between the tsunami waves and the numerous bathymetric structures like the Loyalty and Norfolk ridges in the neighborhood of the source, the tsunami propagating toward the south of Grande Terre and the Isle of Pines is captured by these structures acting like waveguides, allowing it to propagate to the north-northwest, especially in the Loyalty Islands and along the east coast of Grande Terre. A similar observation results from the propagation in the Vanuatu islands, from Aneityum to Efate.

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Section: Bathymetric Gridsmentioning

confidence: 99%

The M_w 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

Roger

Pelletier

Duphil

et al. 2021

Nat. Hazards Earth Syst. Sci.

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show abstract

“…The Kanyakumari district is stated to be facing grave anthropogenic challenges like population growth and encroachment activities. Apart from this on the other hand it also faces various environmental challenges such as SLR, saline intrusion, loss of coastal landforms due to shoreline changes especially because of coastal erosion, declining sediment load, saline intrusion, contamination of coastal aquifer due to hasty alteration in LULC persuaded by climate change (Hentry et al 2010;Kaliraj et al 2017). The Kanyakumari district has a total of 17 coastal villages that are encompassed in three taluks viz., Agasteeswarm (7), Kalkulam (4), and Killiyoor (6).…”

Section: Resultsmentioning

confidence: 99%

Implications of sea-level rise on the coastal villages of Kanyakumari District, Tamil Nadu, India: A geospatial perspectives

Veeran,

Swornamma,

Balasubramaniyan

2024

Preprint

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It’s a realistic approach with the coastline geometry of the sea level rise by statistical analysis of aerial data and concludes with the coastal elevation effects on the different segments of the coastal regions at the village level in Kanyakumari district in Tamil Nadu, India. The physical responses of the coastal zones to extract the coastal landforms of Kanyakumari, India by the comprehensive analysis of inundation scenarios, can find out the risk factors of relative sea level rise. The study area was encompassed into three taluks (Agastheeswaram, Kalkulam, and Killiyoor) and derived into 17 revenue coastal villages for the Land use /Landover (LU/LC) prepared from the satellite imagery with the digital elevation model, The sea level rise scenarios were generated into four class, such as very high (-2m to 0m), high (0m to 0.5m), moderate (0.5m to 1.0m), and low (1.0m). Among the three taluks in the study area, the Agastheeswaram taluk will be inundated 1132.23 ha (10.76%) of the coastal area and Killiyoor taluk will be inundated 327.99 ha (5.39%) of the coastal area are under immediate risk of 0.5m rise in sea-level. Overall, this study exposed significant increases: more than 17% of the coastal population living in the Low Elevation Coastal Zone of the Kanyakumari coast will be exposed to future sea level inundation.

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“…Hentry, Chandrasekar, Saravanan, and Dajkumar Sahayam (2010) analyzed the influence of geomorphology and bathymetry on the effects, based on the estimate that the tsunami wave front, which originated from Sumatra, was diffracted by the island of Sri Lanka, which diverted some of the waves to the southern part of the west coast of India. The combined refraction-diffraction process as the wave front propagated in the shelf water of the west coast could have caused convergence and divergence zones, Physical Geography 425 leading to considerable variations in wave intensity along the coast.…”

Section: Resultsmentioning

confidence: 99%

What drives nearshore sediment transport controls on the depletion of beach placers at Manavalakurichi, Southwest Coast of India?

et al. 2014

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What drives nearshore sediment transport controls on the depletion of beach placers at Manavalakurichi, Southwest Coast of India?, Physical Geography, 35:5,[411][412][413][414][415][416][417][418][419][420][421][422][423][424][425][426][427][428] To link to this article: http://dx.An in-depth analysis has been made to simulate hydrodynamic scenarios for understanding the nearshore sediment transport controls of placer mineral depletion at Manavalakurichi, India. From the analyses of topographic configuration (extracted from Hydrographic Nautical Chart No. 2048 and data generated during year 2010), we inferred that the 5-m isobaths had broadened and exhibited shallowness. Distances between the coastline and the isobaths were found to have increased significantly over the past five decades. Along with this, the 10 and 20-m contours were found to have shifted about 35-100 m horizontally landward. These changes led to severe sediment deposition in these regions due to the changed wave energy levels and refraction patterns. Numerical simulations linking bathymetry, hydrodynamics, sediment load, and significant wave heights revealed that changes in bathymetry would amplify the wave heights and convergence of wave energy. Associated removal of sand from the high-energy zones will eventually lead to sediment starvation situations and depletion of placers in the adjacent beaches. As the observed trends of depletion generate great concern, detailed oceanographic investigations should be taken up immediately in the region. Fine-resolution hydrodynamic datasets should prove useful for further evaluating the physical responses of the system to the altered geometry and for exploring remedial measures for restoring the heavy mineral content of the beach sand.

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Influence of geomorphology and bathymetry on the effects of the 2004 tsunami at Colachel, South India

Cited by 17 publications

References 3 publications

The M_w 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

The M_w 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

Implications of sea-level rise on the coastal villages of Kanyakumari District, Tamil Nadu, India: A geospatial perspectives

What drives nearshore sediment transport controls on the depletion of beach placers at Manavalakurichi, Southwest Coast of India?

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Influence of geomorphology and bathymetry on the effects of the 2004 tsunami at Colachel, South India

Cited by 17 publications

References 3 publications

The Mw 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

The Mw 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

Implications of sea-level rise on the coastal villages of Kanyakumari District, Tamil Nadu, India: A geospatial perspectives

What drives nearshore sediment transport controls on the depletion of beach placers at Manavalakurichi, Southwest Coast of India?

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The M_w 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling

The M_w 7.5 Tadine (Maré, Loyalty Islands) earthquake and related tsunami of 5 December 2018: seismotectonic context and numerical modeling