scholarly journals Risk Assessment at Puerto Vallarta due to a Local Tsunami.

Author(s):  
Elizabeth Trejo Gomez ◽  
Francisco Javier Núñez-Cornú

Abstract The Jalisco region in western Mexico is one of the most seismically active in the country. The city of Puerto Vallarta is located at Bahía de Banderas on the northern coast of Jalisco., Currently there exists a Seismic Gap in the Northern coast of Jalisco (Vallarta Gap). Historically seismogenic tsunamis have affected the coast of Jalisco. In this work, the risk due to a local tsunami in the city of Puerto Vallarta is a function of the interaction between hazard and vulnerability. We model the tsunami hazard, generation and propagation, using the initial conditions for a great earthquake (Mw ≥ 8.0) similar to those that occurred in 1787 at Oaxaca and in 1995 at Tenacatita Bay, Jalisco. Vulnerability is estimated with available data for the years 2010–2015 with sociodemographic variables and the location of government, commercial or cultural facilities. The area with the highest vulnerability and risk is between the valleys of the Ameca and Pitillal Rivers, extending to a distance greater than 5.1 km from the coastline and affecting an area of 30.55 km2. This study does not consider the direct damage caused by the tsunamigenic earthquake and aftershocks; it assumes that critical buildings in the region, mostly hotels, would not collapse after the earthquake and could serve as a refuge for its users. The first (It) tsunami wave arrives to Puerto Vallarta (Cuale) 19 min after the earthquake with a height (Hi) of 3.7 m, the Run Up (At) arrives 74 min after earthquake with a height (Hr) of 5.6 m.

2012 ◽  
Vol 12 (1) ◽  
pp. 151-163 ◽  
Author(s):  
A. Grezio ◽  
P. Gasparini ◽  
W. Marzocchi ◽  
A. Patera ◽  
S. Tinti

Abstract. We present a first detailed tsunami risk assessment for the city of Messina where one of the most destructive tsunami inundations of the last centuries occurred in 1908. In the tsunami hazard evaluation, probabilities are calculated through a new general modular Bayesian tool for Probability Tsunami Hazard Assessment. The estimation of losses of persons and buildings takes into account data collected directly or supplied by: (i) the Italian National Institute of Statistics that provides information on the population, on buildings and on many relevant social aspects; (ii) the Italian National Territory Agency that provides updated economic values of the buildings on the basis of their typology (residential, commercial, industrial) and location (streets); and (iii) the Train and Port Authorities. For human beings, a factor of time exposition is introduced and calculated in terms of hours per day in different places (private and public) and in terms of seasons, considering that some factors like the number of tourists can vary by one order of magnitude from January to August. Since the tsunami risk is a function of the run-up levels along the coast, a variable tsunami risk zone is defined as the area along the Messina coast where tsunami inundations may occur.


2011 ◽  
Vol 1 (32) ◽  
pp. 26 ◽  
Author(s):  
Torsten Schlurmann ◽  
Widjo Kongko ◽  
Nils Goseberg ◽  
Danny Hilman Natawidjaja ◽  
Kerry Sieh

Near-field tsunami propagation both in shallow water environments and bore-like wave propagation on land are conducted in this study to obtain fundamental knowledge on the tsunami hazard potential in the city of Padang, Western Sumatra, Republic of Indonesia. As the region proves a huge seismic moment deficit which has progressively accumulated since the last recorded major earthquakes in 1797 and 1833, this investigation focuses on most reasonable seismic sources and possibly triggered nearshore tsunamis in order to develop upgraded disaster mitigations programs in this densely-populated urban agglomeration located on the western shore of Sumatra Island. Observations from continuous Global Positioning Satellite (cGPS) systems and supplementary coral growth studies confirm a much greater probability of occurrence that a major earthquake and subsequent tsunami are likely to strike the region in the near future. Newly surveyed and processed sets of geodata have been collected and used to progress most plausible rupture scenarios to approximate the extent and magnitudes of a further earthquake. Based upon this novel understanding, the present analysis applies two hydronumerical codes to simulate most probable tsunami run-up and subsequent inundations in the city of Padang in very fine resolution. Run-up heights and flow-depths are determined stemming from these most plausible rupture scenarios. Evaluation of outcome and performance of both numerical tools regarding impacts of surge flow and bore-like wave fronts encountering the coast and inundating the city are thoroughly carried out. Results are discussed not only for further scientific purposes, i.e. benchmark tests, but also to disseminate main findings to responsible authorities in Padang with the objective to distribute the most probable dataset of plausible tsunami inundations as well as to address valuable insights and knowledge for effective counter measures, i.e. evacuation routes and shelter building. Following evacuation simulations based on rational assumptions and simplifications reveal a most alerting result as about 260.000 people are living in the highly exposed potential tsunami inundation area in the city of Padang of which more than 90.000 people will need more than 30 min. to evacuate to safe areas.


2021 ◽  
pp. 103910
Author(s):  
Joaquin P. Moris ◽  
Andrew B. Kennedy ◽  
Joannes J. Westerink

1995 ◽  
Vol 27 (10) ◽  
pp. 1647-1665 ◽  
Author(s):  
J Portugali ◽  
I Benenson

We suggest considering the city as a complex, open, and thus self-organized system, and describing it by means of a cell-space model. A central property of self-organizing systems is that they are not controllable—not by individuals, nor by economic, political, and planning institutions. The city, in this respect, is complex and untamable. Inability to recognize and accept this property is one of the reasons for the difficulties and problems of modernist town planning. The theory and model we present are built to describe the urban process as a historical one in which, given identical initial conditions, each simulation run is unique and never fully repeats itself. From the point of view of urban policy and planning, our heuristic model can guide decisionmakers by answering the following question: ‘given the initial conditions of an inflow of new immigrants (that is, from the ex-USSR), what possible urban scenarios can result, and what are their global structural properties?’.


2018 ◽  
Vol 7 (3) ◽  
pp. 1233
Author(s):  
V Yuvaraj ◽  
S Rajasekaran ◽  
D Nagarajan

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.  


2021 ◽  
Vol 331 ◽  
pp. 04006
Author(s):  
Leli Honesti ◽  
Meli Muchlian

A tsunami hazard is an adverse event that causes damage to properties and loss of life. The problem in assessing a tsunami risk zone for a small area is significant, as available tsunami inundation zone data does not give detailed information for tsunami inundation and run-up in every nested grid. Hence, this study aims to establish a tsunami risk map in the Pasir Jambak sub-district, Padang, Indonesia. The map was carried out in every nested grid point of the area and on a large scale (1:5,000). The TUNAMI N3 program was used for the simulation of the tsunami inundation. A tsunami assessment was made through simulations in nine scenarios of fault parameter data for Sipora block earthquakes. The result of the study provides a tsunami inundation map. Furthermore, this tsunami inundation map can be used for communities, local authorities, government, and others for many studies, and decision-makers can come up with mitigation plans for a small study area.


2015 ◽  
Vol 9 (6) ◽  
pp. 6471-6493 ◽  
Author(s):  
M. P. Lüthi ◽  
A. Vieli

Abstract. Glacier calving can cause violent impulse waves which, upon landfall, can lead to destructive tsunami-like waves. Here we present data acquired during a calving event from Eqip Sermia, an ocean-terminating glacier in West Greenland. During an exceptionally well documented event, the collapse of 9 × 105 m3 ice from a 200 m high ice cliff caused an impulse wave of 50 m height, traveling at a speed of 25–30 m s-1. This wave was filmed from a tour boat in 800 m distance from the calving face, and simultaneously measured with a terrestrial radar interferometer and a tide gauge. Tsunami wave run-up height on the steep opposite shore in 4 km distance was 10–15 m, destroying infrastructure and eroding old vegetation. These observations indicate that such high tsunami waves are a recent phenomenon in the history of this glacier. Analysis of the data shows that only moderately bigger tsunami waves are to be expected in the future, even under rather extreme scenarios.


2021 ◽  
Author(s):  
Alisa Medvedeva ◽  
Igor Medvedev

<p>A regional model of tsunami seismic sources in the zone of the Main Caucasian thrust has been developed. The parameters of probable models of seismic sources and their uncertainties were estimated based on the available data on historical earthquakes and active faults of the region. The scenario modeling technique was used for the tsunami zoning of the Caspian Sea coast. The time period covered by the model catalog of earthquakes used to calculate the generation and propagation of tsunamis is about 20 000 years, which is longer than the recurrence periods of the strongest possible earthquakes. The recurrence graphs of the calculated maximum tsunami heights for the entire sea coast were plotted. On their basis, the maximum heights of tsunami waves on the coast were calculated with recurrence periods of 250, 500, 1000 and 5000 years and the corresponding survey maps of the tsunami zoning of the Caspian Sea were created. The algorithm for calculating the tsunami run-up on the coast is improved, taking into account the residual (postseismic) displacements of the bottom and land relief. Estimates of tsunami hazard for the coast near the city of Kaspiysk were carried out: within the framework of the deterministic approach, the maximum wave heights and run-up distance were calculated. It is shown that the deterministic approach slightly overestimates the maximum heights of tsunami waves with certain return periods. It is shown that changes in the mean sea level can affect the features of the propagation of tsunami waves in the Caspian Sea. Thus, at an average sea level of -25-26 m, the Kara-Bogaz-Gol Bay is linked with the entire sea through a narrow strait. It leads to the propagation of tsunami waves into the water area of the bay and a decrease in wave height on the eastern coast of the sea. When the mean sea level decreases below -27 m, the positive depths in the strait disappear and water exchange through the strait stops, and the wave height in this part of the sea increases.</p>


1996 ◽  
Vol 86 (6) ◽  
pp. 1655-1666 ◽  
Author(s):  
S. K. Singh ◽  
M. Ordaz ◽  
L. E. Pérez-Rocha

Abstract The description of the great earthquake of 19 June 1858 is unusual: damage and high intensities were reported both in the state of Michoacan and in Mexico City. Although a coastal epicenter for this earthquake cannot be ruled out, the reports agree better with an intermediate-depth (about 50 km), normal-faulting event in the subducted Cocos plate. A careful examination of the reports of this event and other normal-faulting events below the Mexican altiplano suggests that a likely location is 18.0 °N, 100.8 °W, near the epicenter of the 6 June 1964 (M7.3, H = 55 km) event. This location is 220 km SW of the city. The magnitude of the earthquake is estimated to be about 7.7. We synthesize expected ground motions in CU, a hill-zone site in the city, from an event similar to that of 1858, using records from the 23 May 1994 earthquake (18.0 °N, 100.6 °W, H = 50 km, M5.7) as an empirical Green's function and stress parameter, Δσ, of 50, 160, and 300 bar. The expected peak horizontal acceleration in CU of Δσ = 160 bar is about 30 gals. Similar acceleration was recorded in CU during the 1985, Michoacan earthquake (M8.0). We compute expected ground motions at many sites in Mexico City using empirical transfer functions and random vibration theory and compare these motions and the expected damage in the city with those from the 1985 Michoacan earthquake. Results show that the overall expected damage during the postulated earthquake is ⅔ and 1⅓ of that during the Michoacan earthquake for Δσ = 160 and 300 bar, respectively. A greater percentage of low-rise construction, which constitute about 80% of the total in the city, will be damaged during the postulated earthquake than during the Michoacan earthquake. The expected ground motions for Δσ = 50 bar are smaller at all periods than those from the Michoacan earthquake. As the present building code for Mexico City contemplates coastal earthquakes of magnitude greater than 8.0, the case of Δσ = 50 bar is not of interest in this article. This preliminary study suggests a need for a more careful evaluation of expected ground motion in the Valley of Mexico from the postulated earthquake and its impact on the current design spectra of the city.


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