scholarly journals The Horseshoe Abyssal plain Thrust could be the source of the 1755 Lisbon earthquake and tsunami

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Sara Martínez-Loriente ◽  
Valentí Sallarès ◽  
Eulàlia Gràcia

AbstractThe southwest Iberia margin is widely believed to have hosted the 1755 Great Lisbon earthquake and ensuing tsunami, one of the most destructive natural events in European history. Here we combine geophysical data and numerical tsunami modelling to investigate the source and mechanism responsible for this event. We find that an intra-plate, lithospheric¬-scale thrust fault located at the Horseshoe Abyssal Plain coincides with the location and focal mechanisms of the largest regional earthquakes and is likely to have suitable dimensions and fault-rock properties to account for the magnitude of the 1755 event. We present tsunami simulations with this fault as the source, and find that they reproduce reported tsunami energy propagation patterns, arrival-times and run up heights more successfully than other modelled sources. We propose that a reverse dip-slip mechanism on the northwest verging Horseshoe Abyssal plain Thrust, combined with the two-state mechanical behaviour of serpentinite, is the most likely candidate for the source of the 1755 Great Lisbon earthquake and for other recent large regional earthquakes.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sherif M. Hanafy ◽  
Hussein Hoteit ◽  
Jing Li ◽  
Gerard T. Schuster

AbstractResults are presented for real-time seismic imaging of subsurface fluid flow by parsimonious refraction and surface-wave interferometry. Each subsurface velocity image inverted from time-lapse seismic data only requires several minutes of recording time, which is less than the time-scale of the fluid-induced changes in the rock properties. In this sense this is real-time imaging. The images are P-velocity tomograms inverted from the first-arrival times and the S-velocity tomograms inverted from dispersion curves. Compared to conventional seismic imaging, parsimonious interferometry reduces the recording time and increases the temporal resolution of time-lapse seismic images by more than an order-of-magnitude. In our seismic experiment, we recorded 90 sparse data sets over 4.5 h while injecting 12-tons of water into a sand dune. Results show that the percolation of water is mostly along layered boundaries down to a depth of a few meters, which is consistent with our 3D computational fluid flow simulations and laboratory experiments. The significance of parsimonious interferometry is that it provides more than an order-of-magnitude increase of temporal resolution in time-lapse seismic imaging. We believe that real-time seismic imaging will have important applications for non-destructive characterization in environmental, biomedical, and subsurface imaging.


2019 ◽  
Vol 19 (12) ◽  
pp. 2781-2794 ◽  
Author(s):  
Wahyu Widiyanto ◽  
Purwanto B. Santoso ◽  
Shih-Chun Hsiao ◽  
Rudy T. Imananta

Abstract. An earthquake with a magnitude of Mw=7.5 that occurred in Sulawesi, Indonesia, on 28 September 2018 triggered liquefaction and tsunamis that caused severe damage and many casualties. This paper reports the results of a post-tsunami field survey conducted by a team with members from Indonesia and Taiwan that began 13 d after the earthquake. The main purpose of this survey was to measure the run-up of tsunami waves and inundation and observe the damage caused by the tsunami. Measurements were made in 18 selected sites, most in Palu Bay. The survey results show that the run-up height and inundation distance reached 10.7 m in Tondo and 488 m in Layana. Inundation depths of 2 to 4 m were common at most sites and the highest was 8.4 m in Taipa. The arrival times of the tsunami waves were quite short and different for each site, typically about 3–8 min from the time of the main earthquake event. This study also describes the damage to buildings and infrastructure and coastal landslides.


Author(s):  
Susanne Sperrevik ◽  
Paul A. Gillespie ◽  
Quentin J. Fisher ◽  
Trond Halvorsen ◽  
Rob J. Knipe

2020 ◽  
pp. petgeo2020-034
Author(s):  
E. A. H. Michie ◽  
A. P. Cooke ◽  
I. Kaminskaite ◽  
J. C. Stead ◽  
G. E. Plenderleith ◽  
...  

A significant knowledge gap exists when analysing and predicting the hydraulic behaviour of faults within carbonate reservoirs. To improve this, a large database of carbonate fault rock properties has been collected from 42 exposed faults, from seven countries. Faults analysed cut a range of lithofacies, tectonic histories, burial depths and displacements. Porosity and permeability measurements from c. 400 samples have been made, with the goal of identifying key controls on the flow properties of fault rocks in carbonates. Intrinsic and extrinsic factors have been examined, such as host lithofacies, juxtaposition, host porosity and permeability, tectonic regime, displacement, and maximum burial depth, as well as the depth at the time of faulting. The results indicate which factors may have had the most significant influence on fault rock permeability, improving our ability to predict the sealing or baffle behaviour of faults in carbonate reservoirs. Intrinsic factors, such as host porosity, permeability and texture, appear to play the most important role in fault rock development. Extrinsic factors, such as displacement and kinematics, have shown lesser or, in some instances, a negligible control on fault rock development. This conclusion is, however, subject to two research limitations: lack of sufficient data from similar lithofacies at different displacements, and a low number of samples from thrust regimes.Thematic collection: This article is part of the Fault and top seals collection available at: https://www.lyellcollection.org/cc/fault-and-top-seals-2019


2006 ◽  
Vol 14 (2) ◽  
pp. 193-205 ◽  
Author(s):  
A. RIBEIRO ◽  
L. MENDES-VICTOR ◽  
J. CABRAL ◽  
L. MATIAS ◽  
P. TERRINHA

The 1755 Lisbon earthquake and tsunami had one of the highest magnitudes in the history of Europe. The source mechanism requires generation at a subduction zone. Intensity distribution and tsunami modelling excludes the Gorringe Bank as a source area and suggests generation by the incipient convergence of the Atlantic with the Southwest Iberia and Morocco margin rather than at the less active Gulf of Cadiz Accretionary Prism. The comparison with the 2004 Sumatra earthquake and tsunami supports this interpretation. A tsunami warning alert system is urgent for the Atlantic.


2020 ◽  
Author(s):  
Richard Marcer ◽  
Camille Journeau ◽  
Kévin Pons

<p>This work has been performed within the framework of the TANDEM project (Tsunamis in northern AtlaNtic: Definition of Effects by Modelling) which is dedicated to the appraisal of coastal effects due to tsunami waves on the French coastlines. One of the identified objectives of TANDEM consisted in designing, adapting and validating numerical codes for tsunami hazard assessment, addressing the various stages of a tsunami event: generation, propagation, run-up and coastal inundation.</p><p>PRINCIPIA has been working on the development and qualification of two in-house CFD software’s: a 2D Saint-Venant model (often called NLSW for Non-Linear Shallow Water) using an Adaptive Mesh Refinement (AMR) for simulation of large scale tsunami propagation from the source up to coastal scale, and a 3D Navier-Stokes model dedicated to tsunami coastal impact modelling.</p><p>An overview of the results obtained with both codes aiming at being applicable to tsunami modelling, is presented. The validation process has been done on several academic test cases having experimental data for comparisons, as the breaking of a solitary wave on a reef, the generation of a long wave induced by a vertical bloc (massive cliffs, ice bodies) falling down an underlying water volume, the tsunami generation due to a submarine landslide and the tsunami impact on a coastal city.</p><p>A real case simulation is concerned as well, the devastating 2011 Tohoku event which is compared with in-situ data.</p><p>The work was supported by the Tandem project in the frame of French PIA grant ANR-11-RSNR-00023.</p>


Author(s):  
Dwi Pujiastuti ◽  
Rahmad Aperus ◽  
Rachmad Billyanto

<p class="ISI"><strong>Abstract</strong> Tsunami modeling research has been done on the coast of Bengkulu using software L-2008 and Travel Time Tsunami (TTT). Earthquake historical data that used in this research is the earthquake in Bengkulu on September 12, 2007 which is obtained from BMKG and the USGS. This research is aimed to determine the height (run up) and travel time of the tsunami on the coast of Bengkulu as the tsunami disaster mitigation efforts. Tsunami modelling has been done by validate the run up using tide gauge  data in the area of Padang, Muko-Muko, and Kaur.  In this research used magnitude scenario are 8 M<sub>w</sub>, 8.5 M<sub>w</sub> and 9 M<sub>w</sub>. Local tsunami effect observed were 10 areas along the coast region Bengkulu. Tsunami modeling of Bengkulu in September 12, 2007 results the run up value which is close to the run up value of the measurements. From the modelling result obtained that the quickest area impacted by the tsunami is Enggano Island   which is 27  minutes 46  seconds from earthquake.  The highest tsunami run up value is located in the Bengkulu city. The run up values by using the scenario of magnitude 8M<sub>w</sub> is  2.07 m, 8.5 M<sub>w</sub> is  4.05 m and 9 M<sub>w</sub> is 9.83 m.</p><p class="54IsiAbstractCxSpFirst"> </p><p class="54IsiAbstractCxSpLast"><strong>Keywords:</strong>   tsunami, modelling, software L-2008, software TTT, run up</p><p class="ISICxSpFirst"><strong> </strong></p><p class="ISICxSpLast"><strong>Abstrak</strong> Telah dilakukan penelitian pemodelan tsunami di pesisir Pantai Bengkulu dengan menggunakan <em>software</em><em> </em>L-2008 dan <em>Travel Time Tsunami </em>(TTT). Data historis gempa bumi yang digunakan dalam penelitian ini adalah gempa bumi Bengkulu 12 September 2007 yang diperoleh dari BMKG dan USGS. Penelitian ini bertujuan untuk menentukan tinggi (<em>run up</em>) dan waktu tempuh gelombang tsunami di pesisir Pantai Bengkulu sebagai upaya mitigasi bencana tsunami. Sebagai validasi digunakan data <em>run up </em>stasiun <em>tide gauge yang </em>berlokasi di Padang, Muko-muko dan Kaur. Dalam penelitian ini dilakukan pemodelan tsunami untuk mengestimasi tinggi <em>run up</em><em> </em>dan waktu tempuh penjalaran gelombang tsunami menggunakan skenario magnitudo 8 M<sub>w</sub>, 8,5 M<sub>w</sub> dan 9 M<sub>w</sub>. Sebagai titik tinjau digunakan 10  daerah di sepanjang pantai wilayah Bengkulu. Hasil pemodelan menunjukkan  bahwa nilai <em>run up</em>  tsunami  yang diperoleh mendekati nilai <em>run up</em> hasil pengukuran. Daerah dengan waktu tercepat dihantam gelombang tsunami adalah Pulau Enggano dengan waktu tempuh 27 menit dan 46 detik. <em>Run up</em> tertinggi terjadi di  Kota Bengkulu. dengan  nilai <em>run up</em> yang diperoleh adalah 2,07 m untuk skenario 8 M<sub>w</sub>, 4,05 untuk skenario 8,5 M<sub>w  </sub>dan9,83 m untuk skenario 9 M<sub>w</sub>.</p><p><strong> </strong></p><p><strong>Kata kunci:</strong> :tsunami, pemodelan, <em>software </em>L-2008, <em>software </em>TTT, <em>run up</em></p>


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