Lake Tsunamis: Causes, Consequences and Hazard investigated in a multidisciplinary project

2020 ◽  
Author(s):  
Katrina Kremer ◽  
Flavio S. Anselmetti ◽  
Paola Bacigaluppi ◽  
Robert M. Boes ◽  
Frederic M. Evers ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Mass Movement ◽  
Field Work ◽  
Current Status ◽  
Mass Movements ◽  
Ocean Bottom ◽  
Tsunami Deposits ◽  
Tsunami Waves ◽  
Lake Lucerne ◽  
Run Up

<p>Tsunamis can occur in lacustrine environments, similar to marine settings. In lake settings, these tsunamis are mainly generated by mass-movement processes displacing large volumes of water, and triggered by seismic or aseismic phenomena. In Swiss lakes, several historical tsunamis are reported. Some of the most prominent examples are: the 563 AD Lake Geneva tsunami presumably caused by a rockfall-induced delta failure, the 1601 AD Lake Lucerne tsunami caused by earthquake-triggered sublacustrine mass movements, and the 1687 AD Lake Lucerne tsunami that was caused by a delta failure.</p><p> </p><p>Nowadays, the shorelines of many Swiss lakes are densely populated and host important infrastructures. The occurrence of lake tsunamis in Switzerland is known, however, we still miss a workflow to assess the hazard related to tsunamis. Within the framework of a multidisciplinary project (Lake Tsunamis: Causes, Consequences and Hazard), funded by the Swiss National Science Foundation and the Federal Office for the Environment, we aim towards better understanding lake-tsunami processes using Swiss lakes as laboratories.</p><p> </p><p>The major objectives of this project are to investigate a) the diverse causes of lake tsunamis, b) the geotechnical and sedimentological properties of unstable slope sediment, c) the potentially unstable sediment volumes on charged slopes, d) the wave generation, propagation and shore run-up, e) the onshore and shallow offshore tsunami deposits and d) their related hazard.</p><p> </p><p>Since 2018, extensive field work using ocean bottom seismometers and cone penetration tests, as well as laboratory tests on sediment sample have been performed to assess the slope stability during seismic shaking on Lake Lucerne. Tsunami waves have been reproduced at laboratory scale to benchmark the numerical simulations of generation, propagation and run-up of tsunamis in lakes. To characterize and date historical and prehistorical tsunami deposits, on and off-shore sediment cores have been retrieved at Lake Lucerne, Geneva, Zurich and Sils. A first work-flow to assess the tsunami hazard related to earthquake-triggered sublacustrine mass movements is proposed. In this contribution, we will summarise the current status of this project.</p>

scholarly journals A tsunamigenic delta collapse and its associated tsunami deposits in and around Lake Sils, Switzerland

2021 ◽  
Author(s):  
Valentin Nigg ◽  
Stephan Wohlwend ◽  
Michael Hilbe ◽  
Benjamin Bellwald ◽  
Stefano C. Fabbri ◽  
...  
Keyword(s):  
Coastal Plain ◽  
Sediment Cores ◽  
Mass Movement ◽  
Coarse Grained ◽  
Sediment Provenance ◽  
Lake Basin ◽  
Tsunami Deposits ◽  
Wave Heights ◽  
Event Deposit ◽  
Common Era

AbstractLarge lacustrine mass movements and delta collapses are increasingly being considered as potential tsunamigenic sources and therefore hazardous for the population and infrastructure along lakeshores. Although historical reports document tsunami events in several lakes in Switzerland, and although the propagation of lake tsunamis has been studied by numerical wave modeling, only little is known about on- and offshore lacustrine tsunami deposits. In Lake Sils, Switzerland, a large prehistoric mass-movement deposit originating from the Isola Delta with a minimum estimated volume of 6.5 × 106 m3 and a basinal thickness of > 6 m in the seismic record has been identified by previous studies and radiocarbon dated to around 700 Common Era. Here, we combine (i) comprehensive sedimentological investigation of sediment cores recovered from the on- and offshore settings, (ii) mineralogical fingerprinting of the inflows from key catchments to characterize sediment provenance, and (iii) numerical tsunami modeling, to test the hypothesis of a tsunamigenic delta collapse in Lake Sils. We observe a clastic event deposit consisting of coarse-grained, fining-upward sand overlying an organic-rich peat deposit in the shallow water. This layer thins and fines landward on the coastal plain. Toward the deeper water (20–40 m), the deposit transforms into a thicker and more heterogeneous sediment package with multiple sequences of fining-upward sand and a well-pronounced clay cap at the top. Radiocarbon dating of the peat underlying the event deposit yields a maximum age of 225–419 calibrated  Common Era. The tsunami models, which indicate wave heights reaching up to 5 m, simulate areas of inundation that coincide with the location of event deposits. Based on our results, we propose that the historically undocumented Isola Delta collapse generated a basin-wide tsunami that inundated the lakeshore, transporting large amounts of unconsolidated sediment along the lakeshore toward the coastal plain and into the deeper lake basin.

scholarly journals Stability assessment of submerged lateral and deltaic slopes in Lake Lucerne

2020 ◽  
Author(s):  
Anastasiia Shynkarenko ◽  
Sylvia Stegmann ◽  
Katrina Kremer ◽  
Paolo Bergamo ◽  
Walter Imperatori ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Mass Movement ◽  
Slope Stability Analysis ◽  
Tsunami Hazard ◽  
Critical Conditions ◽  
Mass Movements ◽  
Lake Lucerne ◽  
Geotechnical Investigations

<p>Numerous studies indicate that tsunamis do not only occur in oceans but also in lakes. Lake Tsunamis are mainly caused by sublacustrine and subaerial mass movements that can be triggered by seismic or aseismic processes (Schnellmann et al. 2002, Strasser et al. 2007, Kremer at al. 2012, Hilbe and Anselmetti 2015). Such tsunamis can have devastating effects on the surrounding population and infrastructure.</p><p>To assess the tsunami hazard triggered by sublacustrine mass movements, the stability of the lake slopes needs to be examined. As a part of the SNSF funded SINERGIA project “Lake Tsunamis: Causes, Controls and Hazard”, we perform the slope stability analysis based on the comprehensive geotechnical in situ and laboratory dataset for the selected sites of Lake Lucerne, Central Switzerland.</p><p>During 2018-2019 dense geotechnical investigations were carried out along slope-perpendicular profiles at 10 sites where the slopes have failed in the past or are susceptible to failure and included more than 130 in-situ free-fall cone penetration tests with pore pressure measurement (CPTu) and laboratory analysis of 30 short sediment cores. Already existing reflection seismic dataset complements these data and provides the thickness of different sediment layers.</p><p>1D undrained, infinite slope stability analysis following Morgenstern and Price (1965) is used to define the Factor of Safety and critical conditions for deltaic and lateral slopes, where different triggers can be responsible for the failure. Based on the conducted analysis, static and dynamic stability together with critical failure conditions for different slopes in Lake Lucerne can be compared.</p><p> </p><p>References:</p><p>Hilbe, M. and Anselmetti, F.S. (2015) Mass Movement-Induced Tsunami Hazard on Perialpine Lake Lucerne (Switzerland): Scenarios and Numerical Experiments. Pure and Applied Geophysics 172, 545-568.</p><p>Kremer, K., Simpson, G., Girardclos, S. (2012) Giant Lake Geneva tsunami in AD 563. Nature Geoscience 5, 756-757.</p><p>Morgenstern, N.R. and Price, V.E. (1965) Analysis of stability of general slip surfaces. Geotechnique 15(1): 79–93.</p><p>Schnellmann, M., Anselmetti, F.S., Giardini, D., McKenzie, J.A., Ward, S.N. (2002) Prehistoric earthquake history revealed by lacustrine slump deposits. Geology 30, 1131–1134.</p><p>Strasser, M., Stegmann, S., Bussmann, F., Anselmetti, F.S., Rick, B., Kopf, A. (2007) Quantifying subaqueous slope stability during seismic shaking: Lake Lucerne as model for ocean margins. Marine Geology 240, 77-97.</p>

scholarly journals Offshore Tsunami Deposits: Evidence from Sediment Cores and Numerical Wave Propagation of the 1601 CE Lake Lucerne Event

2021 ◽  
Author(s):  
Valentin Nigg ◽  
Paola Bacigaluppi ◽  
David Florian Vetsch ◽  
Hendrik Vogel ◽  
Katrina Kremer ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Sediment Cores ◽  
Tsunami Deposits ◽  
Lake Lucerne ◽  
Numerical Wave ◽  
Offshore Tsunami Deposits

Evidence of tsunami deposits in East Tunisia coastline contemporaneous of the AD 365 Crete earthquake: Field data and modelling 

2021 ◽  
Author(s):  
Nejib Bahrouni ◽  
Mustapha Meghraoui ◽  
Hafize Başak Bayraktar ◽  
Stefano Lorito ◽  
Mohamed Fawzi Zagrarni ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Eastern Coast ◽  
Tsunami Deposits ◽  
Alluvial Deposits ◽  
Tsunami Waves ◽  
Sedimentary Deposits ◽  
Beach Rock ◽  
Hazard And Risk ◽  
Run Up ◽  
Crete Earthquake

<p>New field investigations along the East Tunisian near Sfax coastline reveal sedimentary deposits that may account for a catastrophic event. The sedimentary unit is made of sand coarse gravels, limestone beach-rock, mixed with broken shells of marine gastropods and lamellibranch mollusks, bones and organic matter. Near Thyna, at El Amra site located north of Sfax city, 3.2 m to 3.6 m high late Quaternary coastal terraces are spread over the coastline; they contain a catastrophic deposit that often cover archeological sites of the Roman period. The stratigraphic units show a succession of sandy-silty paleosol truncated by 40 to 70-cm-thick catastrophic unit which is covered in some sites by fire remains overlain by a relatively thin (~10 cm) sandy-silty aeolian unit. The sedimentary succession ends with about 1-m-thick of alluvial deposits and paleosol units. Charcoal samples collected at 10 cm below and 4 cm above the catastrophic units provide radiocarbon dating 236 - 385 cal AD and 249 – 541 cal AD (2s), respectively. Radiocarbon ages bracket the catastrophic unit that may refer to the major tsunamigenic earthquake of 21 July 365 (Mw ~ 8) in west Crete (Greece) reported to have inundated coastlines of Sabratha in Libya and Alexandria in Egypt. The nonlinear shallow water Tsunami-HySEA code is used to perform numerical modelling using 2 different seismic sources comparable to that of the AD 365 Crete earthquake. They feature 2 principal mechanisms that accommodate the Nubia-Aegean convergence along the Hellenic Arc, namely a shallowly dipping thrust-faulting on the subduction interface, as well as a steeper splay faulting in the overriding material. The maximum tsunami wave heights distribution calculated along the Tunisia coast peak in both cases at about 3 meters. The run-up caused by these sources, also considering that we have used uniform slip on the causative fault, can be significantly higher. This proves that the tsunami waves may have reached Tunisia where several coastal cities where severely damaged and reported to have stopped their economic activity. With the identification of the 365 tsunami deposits in eastern coast of Tunisia, the tsunami hazard and risk associated with a major earthquake from the western Hellenic subduction zone cannot be ruled out.</p>

scholarly journals Shallow‐Water Tsunami Deposits: Evidence from Sediment Cores and Numerical Wave Propagation of the 1601 CE Lake Lucerne Event

2021 ◽  
Author(s):  
Valentin Nigg ◽  
Paola Bacigaluppi ◽  
David F. Vetsch ◽  
Hendrik Vogel ◽  
Katrina Kremer ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Shallow Water ◽  
Sediment Cores ◽  
Tsunami Deposits ◽  
Lake Lucerne ◽  
Numerical Wave

Seismically Derived Ground Tilts Related to the 2010 Chilean Tsunami

2021 ◽  
Author(s):  
Jui-Chun Freya Chen ◽  
Wu-Cheng Chi ◽  
Chu-Fang Yang
Keyword(s):  
Deep Ocean ◽  
Propagation Model ◽  
Ocean Bottom ◽  
Ocean Bottom Seismometer ◽  
Tsunami Propagation ◽  
Ground Tilt ◽  
Tsunami Waves ◽  
The Pacific ◽  
Seismic Networks ◽  
Back Azimuth

Abstract Developing new ways to observe tsunami contributes to tsunami research. Tidal and deep-ocean gauges are typically used for coastal and offshore observations. Recently, tsunami-induced ground tilts offer a new possibility. The ground tilt signal accompanied by 2010 Mw 8.8 Chilean earthquake were observed at a tiltmeter network in Japan. However, tiltmeter stations are usually not as widely installed as broadband seismometers in other countries. Here, we studied broadband seismic records from Japan’s F-net and found ground tilt signals consistent with previously published tiltmeter dataset for this particular tsunamic event. Similar waveforms can also be found in broadband seismic networks in other countries, such as Taiwan, as well as an ocean-bottom seismometer. We documented a consistent time sequence of evolving back-azimuth directions of the tsunami waves at different stages of tsunami propagation through beamforming-frequency–wavenumber analysis and particle-motion analysis; the outcomes are consistent with the tsunami propagation model provided by the Pacific Tsunami Warning Center. These results shown that dense broadband seismic networks can provide a useful complementary dataset, in addition to tiltmeter arrays and other networks, to study or even monitor tsunami propagation using arrayed methods.

scholarly journals Tsunami wave propagation by voronoi diagram

2018 ◽  
Vol 7 (3) ◽  
pp. 1233
Author(s):  
V Yuvaraj ◽  
S Rajasekaran ◽  
D Nagarajan
Keyword(s):  
Wave Propagation ◽  
Voronoi Diagram ◽  
Tsunami Wave ◽  
Fast Marching Method ◽  
Coastal Regions ◽  
Fast Marching ◽  
Tsunami Waves ◽  
The Finite Difference Method ◽  
Run Up ◽  
Marching Method

Cellular automata is the model applied in very complicated situations and complex problems. It involves the Introduction of voronoi diagram in tsunami wave propagation with the help of a fast-marching method to find the spread of the tsunami waves in the coastal regions. In this study we have modelled and predicted the tsunami wave propagation using the finite difference method. This analytical method gives the horizontal and vertical layers of the wave run up and enables the calculation of reaching time.  

scholarly journals Tsunamis boulders on the rocky shores of Minorca (Balearic Islands)

2017 ◽  
Author(s):  
Francesc X. Roig-Munar ◽  
Josep M. Vilaplana ◽  
Antoni Rodríguez-Perea ◽  
José A. Martín-Prieto ◽  
Bernadí Gelabert
Keyword(s):  
Sea Level ◽  
North Africa ◽  
Numerical Models ◽  
Balearic Islands ◽  
Rocky Shores ◽  
Impact Zone ◽  
Tsunami Waves ◽  
Southeast Coast ◽  
Historical Tsunamis ◽  
Run Up

Abstract. Large boulders have been found on marine cliffs of 24 study areas of Minorca, Balearic Archipelago. These large imbricated boulders, of up to 229 tonnes, are located on platforms that conform the rocky coastline of Minorca, several tenths of meters from the edge of the cliff, up to 15 m above the sea level, and kilometres away from any inland escarpment. They are mostly located on the southeast coast of the island, and numerical models have identified this coastline as a high tsunami impact zone. The age of the boulders in most of the studied localities show a good correlation with historical tsunamis. Age of the boulders, direction of imbrication and estimation of run-up necessary for their placement, indicate dislodging and transport by North Africa tsunami waves that hit the coastline of Minorca.

scholarly journals TSUNAMI PHASE SPEED REDUCTION DUE TO WATER COMPRESSIBILTY

2018 ◽  
pp. 9
Author(s):  
Ali Abdolali ◽  
James T. Kirby
Keyword(s):  
Arrival Time ◽  
Phase Speed ◽  
Propagation Speed ◽  
Frequency Dispersion ◽  
Wave Theory ◽  
Polar Coordinates ◽  
Ocean Bottom ◽  
Tsunami Propagation ◽  
Boussinesq Model ◽  
Tsunami Waves

Most existing tsunami propagation models consider the ocean to be an incompressible, homogenous medium. Recently, it has been shown that a number of physical features can slow the propagation speed of tsunami waves, including wave frequency dispersion, ocean bottom elasticity, water compressibility and thermal or salinity stratification. These physical effects are secondary to the leading order, shallow water or long wave behavior, but still play a quantifiable role in tsunami arrival time, especially at far distant locations. In this work, we have performed analytical and numerical investigations and have shown that consideration of those effects can actually improve the prediction of arrival time at distant stations, compared to incompressible forms of wave equations. We derive a modified Mild Slope Equation for Weakly Compressible fluid following the method proposed by Sammarco et al. (2013) and Abdolali et al. (2015) using linearized wave theory, and then describe comparable extensions to the Boussinesq model of Kirby et al. (2013). Both models account for water compressibility and compression of static water column to simulate tsunami waves. The mild slope model is formulated in plane Cartesian coordinates and is thus limited to medium propagation distances, while the Boussinesq model is formulated in spherical polar coordinates and is suitable for ocean scale simulations.

scholarly journals URBAN SPRAWL IN SMALL CITIES, ANALYSIS OF THE MUNICIPALITY OF SÃO PEDRO (SP): POTENTIALS AND CONSTRAINS

2013 ◽  
pp. 64-73 ◽  
Author(s):  
Priscila Carrara Fracassi ◽  
José Augusto Lollo
Keyword(s):  
Data Collection ◽  
Present Article ◽  
Urban Sprawl ◽  
Field Work ◽  
Limiting Factors ◽  
Soil Conditions ◽  
Mass Movements ◽  
Small Cities ◽  
Natural Factors

Urban sprawl in small cities has led to the occupation of unsuitable areas, resulting in peripheralization and in the occupation of fragile environments. In these occupations, the physical characteristics of the environment are often disrespected. In this context, the present article reports on a case study in the municipality of São Pedro, state of São Paulo, Brazil, which presents and discuss a set of natural factors (geological and geomorphological) conditioning the occurrence of erosion and gravitational mass movements, which are limiting factors for urban sprawl. The methodology employed in this study was based on field work, bibliographic research, and data collection, analysis and GIS-based systematization, which allowed for a spatial reading of the urban sprawl to indicate, from different perspectives, how the phenomenon is manifested. Thus, it was possible to draw up a chart highlighting the areas with the greatest potential for occupation and those with restrictions due to their greater susceptibility to erosion and mass movements. The main identified natural factors of restriction were steepness and soil conditions and law enforced restrictions (environmental protection areas).

Sign in / Sign up

Export Citation Format

Share Document