The Continuing Underestimated Tsunami Hazard from Submarine Landslides

2020 ◽  
pp. 343-350
Author(s):  
David R. Tappin ◽  
Stephan T. Grilli
Keyword(s):  
Tsunami Hazard ◽  
Submarine Landslides

Submarine Landslides and Their Tsunami Hazard

2016 ◽  
Vol 49 (1) ◽  
Author(s):  
David R. Tappin
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Submarine Landslide ◽  
Tsunami Hazard ◽  
Publication Date ◽  
Submarine Landslides ◽  
Critical Importance ◽  
Grand Banks ◽  
Landslide Mechanisms ◽  
Landslide Tsunamis

Most tsunamis are generated by earthquakes, but in 1998, a seabed slump offshore of northern Papua New Guinea (PNG) generated a tsunami up to 15 m high that killed more than 2,200 people. The event changed our understanding of tsunami mechanisms and was forerunner to two decades of major tsunamis that included those in Turkey, the Indian Ocean, Japan, and Sulawesi and Anak Krakatau in Indonesia. PNG provided a context to better understand these tsunamis as well as older submarine landslide events, such as Storegga (8150 BP); Alika 2 in Hawaii (120,000 BP), and Grand Banks, Canada (1929), together with those from dual earthquake/landslide mechanisms, such as Messina (1908), Puerto Rico (1928), and Japan (2011). PNG proved that submarine landslides generate devastating tsunamis from failure mechanisms that can be very different, whether singly or in combination with earthquakes. It demonstrated the critical importance of seabed mapping to identify these mechanisms as well as stimulated the development of new numerical tsunami modeling methodologies. In combination with other recent tsunamis, PNG demonstrated the critical importance of these events in advancing our understanding of tsunami hazard and risk. This review recounts how, since 1998, understanding of the tsunami hazard from submarine landslides has progressed far beyond anything considered possible at that time. ▪ For submarine landslide tsunamis, advances in understanding take place incrementally, usually in response to major, sometimes catastrophic, events. ▪ The Papua New Guinea tsunami in 1998, when more than 2,200 people perished, was a turning point in first recognizing the significant tsunami hazard from submarine landslides. ▪ Over the past 2 to 3 years advances have also been made mainly because of improvements in numerical modeling based on older tsunamis such as Grand Banks in 1929, Messina in 1908, and Storegga at 8150 BP. ▪ Two recent tsunamis in late 2018, in Sulawesi and Anak Krakatau, Indonesia, where several hundred people died, were from very unusual landslide mechanisms—dual (strike-slip and landslide) and volcanic collapse—and provide new motivations for understanding these tsunami mechanisms. ▪ This is a timely, state of the art review of landslide tsunamis based on recent well-studied events and new research on older ones, which provide an important context for the recent tsunamis in Indonesia in 2018. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 49 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Tsunami hazard from submarine landslides on the Oregon continental slope

2004 ◽  
Vol 203 (3-4) ◽  
pp. 235-245 ◽  
Author(s):  
B.G. McAdoo ◽  
P. Watts
Keyword(s):  
Continental Slope ◽  
Tsunami Hazard ◽  
Submarine Landslides

scholarly journals Tsunami Hazard Evaluation for the Head of the Gulf of Elat–Aqaba, Northeastern Red Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Amos Salamon ◽  
Eran Frucht ◽  
Steven N. Ward ◽  
Erez Gal ◽  
Marina Grigorovitch ◽  
...  
Keyword(s):  
Red Sea ◽  
Submarine Landslide ◽  
Tsunami Hazard ◽  
Hazard Evaluation ◽  
False Alarms ◽  
Submarine Landslides ◽  
Case Scenario ◽  
Worst Case ◽  
Ground Shaking ◽  
Landslide Tsunami

Unique geological and seismotectonic settings may trigger a multicascading hazard and should be identified beforehand. Such is the head of the Gulf of Elat–Aqaba (HGEA) at the northeastern end of the Red Sea where its geology, tectonics, bathymetry, and earthquake and tsunami history exhibit clear potential for earthquake and submarine-landslide tsunami generation. We thus investigated the possible tsunamigenic sources in the gulf and evaluated the resulting hazard at the HGEA. First, we assembled a bathymetric grid and adopted GeoClaw software to simulate most of the earthquake-tsunami scenarios. Next, we resolved the scheme of the largest possible tsunamigenic earthquakes along the deep basins of the Gulf of Elat (GEA) and the associated Dead Sea rift valley, as well as the potential tsunamigenic submarine landslides in the HGEA. The use of GeoClaw was verified against the 1995 tsunami generated by the Nuweiba Mw 7.2 earthquake, and then operated to simulate a suite of earthquake scenarios. Results showed that the marginal faults of Elat Basin pose the highest tsunami hazard to the Israeli part of the HGEA. To better assess that hazard, we screened the geology and seismotectonics of the HGEA and found that the Elat normal fault presents the worst-case scenario for Elat city. It is capable of generating a multicascading threat of earthquake and submarine-landslide tsunami, local subsidence that can increase inundation, and above all, destructive ground motion. Scenarios of a tsunami caused by the worst-case earthquake on the Elat fault simulated by GeoClaw and Ward’s (Tsunami, The encyclopedia of solid earth geophysics. 2011, 1473–1493) approach, and submarine landslide in the HGEA simulated by Wang et al.’s (Geophys. J. Int., 2015, 201, 1534–1544) ‘Tsunami Squares’ approach, demonstrated waves as high as 4 m along these coasts. Accordingly, we constructed a map of the evacuation zone. We also show that strong ground-shaking and retreat of the sea at the HGEA should be considered a tsunami warning, although false alarms are inevitable. Furthermore, tsunami hazard exists all along the gulf and further assessments are needed to quantify this hazard and increase awareness among the area's population.

Chapter 3 Tsunami hazard with reference to the UK

2020 ◽  
Vol 29 (1) ◽  
pp. 61-80 ◽  
Author(s):  
David Peter Giles
Keyword(s):  
National Level ◽  
Open Water ◽  
Tsunami Hazard ◽  
Mitigation Strategies ◽  
Tsunami Source ◽  
Submarine Landslides ◽  
The People ◽  
Japanese Word ◽  
Northern North Sea ◽  
The Uk

AbstractTsunami present a significant geohazard to coastal and water-body marginal communities worldwide. Tsunami, a Japanese word, describes a series of waves that, once generated, travel across open water with exceptionally long wavelengths and with very high velocities before shortening and slowing on arrival at a coastal zone. Upon reaching land, these waves can have a devastating effect on the people and infrastructure in those environments. With over 12 000 km of coastline, the British Isles is vulnerable to the tsunami hazard. A significant number of potential tsunami source areas are present around the entire landmass, from plate tectonic boundaries off the Iberian Peninsula to the major submarine landslides in the northern North Sea to more localized coastal cliff instability which again has the potential to generate a tsunami. Tsunami can be generated through a variety of mechanisms including the sudden displacement of the sea floor in a seismic event as well as submarine and onshore landslides displacing a mass of water. This review presents those impacts together with a summary of tsunami triggers and UK case histories from the known historic catalogue. Currently, apart from some very sensitive installations, there is very little in the UK in the way of tsunami management and mitigation strategies. A situation that should be urgently addressed both on a local and national level.

scholarly journals Owen Ridge deep-water submarine landslides: implications for tsunami hazard along the Oman coast

2013 ◽  
Vol 13 (2) ◽  
pp. 417-424 ◽  
Author(s):  
M. Rodriguez ◽  
N. Chamot-Rooke ◽  
H. Hébert ◽  
M. Fournier ◽  
P. Huchon
Keyword(s):  
Finite Difference ◽  
Arabian Sea ◽  
Tsunami Hazard ◽  
Potential Hazard ◽  
Submarine Landslides ◽  
Tsunami Generation ◽  
Difference Model ◽  
Tsunami Waves ◽  
Wave Elevation ◽  
Sediment Failure

Abstract. The recent discovery of voluminous submarine landslides along the Owen Ridge may represent a source of tsunami hazard for the nearby Oman coast. We assess the severity of this potential hazard by performing numerical simulations of tsunami generation and propagation from the biggest landslide (40 km3 in volume) observed along the Owen Ridge. A finite-difference model, assimilating the landslide to a visco-plastic flow, simulates tsunami generation. Computation results show that Salalah city (190 000 inhabitants) is impacted by 2.5 m-high tsunami waves one hour after sediment failure. Higher wave elevation values (4 m) are reached in the low populated Sawqara Bay over 80 min after slide initiation. Although large submarine failures along remote oceanic ridges are infrequent, this study reveals an underestimated source of tsunami hazard in the Arabian Sea.

scholarly journals Tsunami hazard from submarine landslides: scenario-based assessment in the Ulleung Basin, East Sea (Japan Sea)

2018 ◽  
Vol 23 (3) ◽  
pp. 439-460 ◽  
Author(s):  
Roger Urgeles ◽  
Jang-Jun Bahk ◽  
Sang-Hoon Lee ◽  
Senay Horozal ◽  
Deniz Cukur ◽  
...  
Keyword(s):  
Japan Sea ◽  
Tsunami Hazard ◽  
East Sea ◽  
Ulleung Basin ◽  
Submarine Landslides

scholarly journals Landslide tsunami hazard in the Indonesian Sunda Arc

2010 ◽  
Vol 10 (3) ◽  
pp. 589-604 ◽  
Author(s):  
S. Brune ◽  
A. Y. Babeyko ◽  
S. Ladage ◽  
S. V. Sobolev
Keyword(s):  
Geophysical Methods ◽  
Tsunami Hazard ◽  
Mass Movements ◽  
Submarine Landslides ◽  
Bottom Pressure ◽  
Indonesian Archipelago ◽  
Catastrophic Earthquake ◽  
Sunda Arc ◽  
Landslide Tsunami ◽  
Tsunami Scenarios

Abstract. The Indonesian archipelago is known for the occurrence of catastrophic earthquake-generated tsunamis along the Sunda Arc. The tsunami hazard associated with submarine landslides however has not been fully addressed. In this paper, we compile the known tsunamigenic events where landslide involvement is certain and summarize the properties of published landslides that were identified with geophysical methods. We depict novel mass movements, found in newly available bathymetry, and determine their key parameters. Using numerical modeling, we compute possible tsunami scenarios. Furthermore, we propose a way of identifying landslide tsunamis using an array of few buoys with bottom pressure units.

Numerical simulation of the July 2010 meteotsunami on the coast of Portugal: Implications for meteotsunami hazard in the NE Atlantic

2020 ◽  
Author(s):  
Jihwan Kim ◽  
Rachid Omira
Keyword(s):  
Tide Gauge ◽  
Incident Angle ◽  
Plate Boundary ◽  
Tsunami Hazard ◽  
Submarine Landslides ◽  
Sea Waves ◽  
Ne Atlantic ◽  
Gaussian Shape ◽  
Ne Atlantic Ocean ◽  
Fast Development

<p>In the NE Atlantic Ocean, the tsunami hazard is mainly associated to large earthquakes occurring along the Azores-Gibraltar plate boundary, to submarine landslides, or even to the flank collapses in the volcanic Islands. The hazard posed by meteotsunami remains less understood in the region. Yet, the Atlantic coasts of Portugal, Spain and France have experienced at least two meteotsunamis on July 2010 and June 2011. On July 6th and 7th 2010, uncommon sea waves were observed along the coast of Portugal. The Portuguese tide-gauge network recorded the sea-level signals showing tsunami-like waves of heights varying from 0.14 to 0.6 m (crest-to-trough) and of periods in the range of 30 to 60 min. Analysis of both oceanic and atmospheric data<br>revealed the occurrence of a meteotsunami on the night of July 6th that propagated from Lagos, south, up to Viana de Castelo, north. Here, we present the first investigation of the 2010 meteotsunami that struck the coast of Portugal. We use the atmospheric pressure data to force the sea surface and numerically generate the 2010 meteotsunami. We then simulate the 2010 meteotsunami propagation over high resolution bathymetric models using a validated NLSW code. The comparison of the simulated waveforms with the records shows satisfactory agreement of wave heights and periods in most stations. Taking the 2010 event as a reference of meteotsunamis along the Portuguese coast, we provide an insight on the meteotsunami hazard posed by<br>events propagating from south to north of the country. This is done by considering a 2D Gaussian shape pressure disturbance that propagates along shelf under varying conditions of speed and incident angle. This allows identifying a number of “hot spots” on the coast of Portugal where the focus of meteotsunami energy is favorable. Our results suggest that meteotsunamis present a real threat on the highly occupied Portuguesecoast and therefore should be considered in tsunami hazard and forecasting strategies of the NE Atlantic countries. This work was supported by the FCT funded project FAST- Development of new forecast skills for meteotsunamis on the Iberian shelf (PTDC/CTA-MET/32004/2017).</p>

Submarine landslide recurrence and links to seismicity on the Gorringe Bank Seamount, Offshore Portugal

2020 ◽  
Author(s):  
Davide Gamboa ◽  
Rachid Omira ◽  
Pedro Terrinha ◽  
Aldina Piedade
Keyword(s):  
Tsunami Hazard ◽  
Submarine Landslides ◽  
Close Link ◽  
Bathymetric Data ◽  
Tsunami Hazard Assessment ◽  
History Of ◽  
Funded Project ◽  
Gorringe Bank ◽  
Seismic Reflection Profiles ◽  
Northern Segment

<p>Submarine landslides are common features occurring on the flanks of seamounts. Often triggered by earthquakes or volcanic activity, such landslides are potential generators of tsunamis that constitute a dire geohazard for coastal communities. Understanding the recurrence history and geomorphology of seamount-flanking landslides and their link to seismic triggers is crucial for tsunami hazard assessment. This work aims at revealing the recurrence history of the landslides on the Gorringe Bank and their role on regional geohazards. Morphologically, the Gorringe Bank is the largest submarine seamount in Europe, with a length of circa 180 km and a height of 5000 m. It is linked to NW-directed thrusting which led to the exhumation of upper mantle lithologies in this major bathymetric structure. Numerous landslide scars are identified on both its northern and southern flanks, yet there is limited evidence of their presence and morphology on modern bathymetric data. A wealth of 2D seismic reflection profiles from offshore Southwest Portugal is here used to analyse the occurrence, timing and morphology of landslides complexes on the northwestern flank of the Gorringe Bank. A widespread frontal landslide complex of approximate Upper Miocene age is present along the whole flank, likely associated with the main phase of uplift. However, the recurrence of expressive submarine landslides in the Plio-Quarternary sequence is generally focused towards the northern segment of the Gorringe Bank. The geographical correlation between the areas of higher landslide number and clusters of seismicity epicentres suggest a close link between the two. This has direct implications for the assessment of landslide-prone locations on the seamount and to regional tsunami hazard models applicable to the Iberian and Northern African margins.</p><p>This work is supported by the FCT funded project MAGICLAND - MArine Geo-hazards InduCed by underwater LANDslides in the SW Iberian Margin (Ref: PTDC/CTA-GEO/30381/2017),</p>

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