71 research outputs found
Losses Associated with Secondary Effects in Earthquakes
The number of earthquakes with high damage and high losses has been limited to around 100 events since 1900. Looking at historical losses from 1900 onward, we see that around 100 key earthquakes (or around 1% of damaging earthquakes) have caused around 93% of fatalities globally. What is indeed interesting about this statistic is that within these events, secondary effects have played a major role, causing around 40% of economic losses and fatalities as compared to shaking effects. Disaggregation of secondary effect economic losses and fatalities demonstrating the relative influence of historical losses from direct earthquake shaking in comparison to tsunami, fire, landslides, liquefaction, fault rupture, and other type losses is important if we are to understand the key causes post-earthquake. The trends and major event impacts of secondary effects are explored in terms of their historic impact as well as looking to improved ways to disaggregate them through two case studies of the Tohoku 2011 event for earthquake, tsunami, liquefaction, fire, and the nuclear impact; as well as the Chilean 1960 earthquake and tsunami event
CEDIM Forensic Disaster Analysis Group (FDA) "Volcano & Tsunami Hunga Tonga" Report No. 1
Der Vulkanausbruch im SĂŒdpazifik (Tongainseln) Mitte Januar 2022 war der weltweit stĂ€rkste seit dem Ausbruch des Pinatubo. Hunga Tonga ist ein groĂer unterseeischer Vulkan etwa 70 km nordwestlich von Tongatapu (SĂŒdwestpazifik). Der Vulkan besteht aus zwei kleinen Inseln, Hunga Tonga und Hunga Ha\u27apai, die durch die jĂŒngsten AusbrĂŒche in den Jahren 1988, 2009 und 2014/2015 miteinander verbunden wurden. Die Eruptionssequenz begann am 20. Dezember 2021 mit einer einzelnen Eruption. Es folgten ein gröĂeres Ereignis am 14. Januar und der Hauptausbruch am 15. Januar gegen 17:15 Uhr Ortszeit (04:15 Uhr UTC). Alle Eruptionen waren mit einem starken Ăberschallknall verbunden. Die Explosion der Haupteruption war ĂŒber Tausende von Kilometern zu hören.
Die Haupteruption löste eine groĂe Massenbewegung aus, die als Quelle fĂŒr den anschlieĂenden Tsunami vermutet wird. Der Tsunami wurde innerhalb von 15 Minuten auf Tongatapu beobachtet und unterbrach die Energieversorgung. Der Tsunami wurde im gesamten Pazifik, im Korallenmeer und im Tasmanischen Meer mit einer Ausbreitung von bis zu 3 m gesichtet.
Es kam zu schweren lokalen Ăberschwemmungen auf Tonga (Run-up von 2 bis 5 m) und lokal zu leichten bis mĂ€Ăigen Ăberschwemmungen entlang des Korallenmeers (< 0,5 â 3 m) und entlang des Pazifiks (0,5 â 1,5 m). Verschiedene Inseln von Tonga wurden teilweise ĂŒberflutet. Die kleinen, unbewohnten Inseln Nuku und Tau wurden vollstĂ€ndig erodiert. Die Ăberschwemmungen auf Tongatapu und Nomuka zerstörten mehrere GebĂ€ude. Korallenriffe und Barriere-Inseln spielten eine wichtige Rolle bei der Abmilderung der Auswirkungen des Tsunami.
Die gröĂten SchĂ€den sind auf den Bruch des Unterseekabels von Fidschi nach Tonga zurĂŒckzufĂŒhren. Die wirtschaftlichen Verluste, die mit einem solchen Ausfall verbunden sind, werden angesichts der Kosten und der Knappheit von Satellitentelefonen groĂ sein. Ein groĂes Problem stellt derzeit die Asche auf der Landebahn von Tongatapu dar, so dass Hilfsflugzeuge meist nicht landen können, um HilfsgĂŒter zu liefern. ZusĂ€tzliche Kosten im Zusammenhang mit den AufrĂ€umarbeiten und der Beseitigung der Asche werden auch in der Landwirtschaft anfallen, ebenso wie mögliche Infrastrukturprobleme durch die Verunreinigung der Wasserversorgung
CEDIM Forensic Disaster Analysis Group (FDA): Noto Earthquake Japan (Jan. 2024)
The 2024 Noto earthquake in Japan, with a magnitude of 7.5 Mw, occurred on 1 January 2024 at 16:10 local time - seven kilometers north-northwest of the coast of Suzu. The strongest intensity was observed on the Noto Peninsula near the epicenter and towards the Sea of Japan; the quake was felt throughout Japan, including the Tokyo area. A USGS landslide model shows a maximum slip of about 3.7 meters along the fault plane with a total length of almost 200 km.
A tsunami warning was issued shortly after the earthquake, with a maximum wave height of 5 meters predicted for the Noto peninsula. The waves that eventually were mostly just under 1 meter, except in the town of Suzu, located in a small bay, where several boats were damaged and houses along the coast were destroyed. Eyewitnesses reported waves as high as 3 meters. Low wave heights were reported from the other coasts of the Sea of Okhotsk.
CEDIM damage estimates (based on JMA/RL intensity data and Shakemap) average 2.3 bn to $11.1 bn). This estimate excludes significant indirect losses, but includes direct damage to buildings, infrastructure, and production. Most of the significant economic damage is concentrated on the Noto Peninsula, particularly in the cities of Wajima, Suzu, and Nanao
Severe thunderstorms with large hail across Germany in June 2019
From 10 to 12 June 2019, severe thunderstorms affected large parts of Germany. Hail larger than golf ball size caused considerable damage, especially in the Munich area where losses amount to EUR 1 billion. This event thus ranks among the ten most expensive hail events in Europe in the last 40âyears. Atmospheric blocking in combination with a moist, unstably stratified air mass provided an excellent setting for the development of severe, hailâproducing thunderstorms across the country.
imageGerman Research Foundation
http://dx.doi.org/10.13039/50110000165
The Asynergies of Structural Disaster Risk Reduction Measures: Comparing Floods and Earthquakes
Traditionally, buildingâlevel disaster risk reduction (DRR) measures are aimed at a single natural hazard. However, in many countries the society faces the threat of multiple hazards. Buildingâlevel DRR measures that aim to decrease earthquake vulnerability can have opposing or conflicting effects on flood vulnerability, and vice versa. In a case study of Afghanistan, we calculate the risk of floods and earthquakes, in terms of average annual losses (AAL), in the current situation. Next, we develop two DRR scenarios, where buildingâlevel measures to reduce flood and earthquake risk are implemented. We use this to identify districts for which DRR measures of one hazard increase the risk of another hazard. We then also calculate the optimal situation between the two scenarios by, for each district, selecting the DRR scenario for which the AAL as a ratio of the total exposure is lowest. Finally, we assess the sensitivity of the total risk to each scenario. The optimal measure differs spatially throughout Afghanistan, but in most districts it is more beneficial to take flood DRR measures. However, in the districts where it is more beneficial to take earthquake measures, the reduction in risk is considerable (up to 40%, while flood DRR measures lead to a reduction in risk by 16% in individual districts). The introduction of asynergies between DRR measures in risk analyses allows policyâmakers to spatially differentiate building codes and other buildingâlevel DRR measures to address the most prevalent risk while not compromising the risk resulting from other hazards
CEDIM Forensic Disaster Analysis Group (FDA): Starkregen Griechenland & Libyen (Sept. 2023)
Von Ende August bis Mitte September 2023 zeichnete sich der Mittelmeerraum durch intensive TiefdrucktĂ€tigkeit aus. Bereits das Tief âErwinâ fĂŒhrte vom 28. bis zum 30. August in Norditalien zu extremen NiederschlĂ€gen, Erdrutschen und Ăberschwemmungen. Triest verzeichnete innerhalb von nur zwei Stunde eine Regenmengen von 100 mm, von der Lombardei bis Trentino gingen gebietsweise 150 bis 200 mm innerhalb eines Tages nieder. Anfang September 2023 traten im westlichen Mittelmeerraum in Nordostspanien enorme Niederschlagsmengen auf, wĂ€hrend sich weiter im Osten das Tief âDanielâ zu formieren begann. âDanielâ entstand an der SĂŒdostflanke eines riesigen blockierenden Hochdruckgebietes ĂŒber Zentraleuropa (âOmegalageâ) und verursachte zunĂ€chst in Griechenland und einige Tage spĂ€ter als sogenannter Medicane in Libyen Sturm, heftige NiederschlĂ€ge und Ăberschwemmungen. Der Sturzregen fĂŒhrte zum Kollaps zweier DĂ€mme, deren Wassermassen sich durch die libysche Hafenstadt Derna wĂ€lzten und Tausenden den Tod brachte. Ganze Stadtteile wurden hinweggespĂŒlt, mehr als 3000 GebĂ€ude wurden völlig zerstört
CEDIM Forensic Disaster Analysis Group (FDA): KahramanmaraĆ & Elbistan Erdbeben TĂŒrkei
Am 6. Februar 2023 ereigneten sich zwei folgenschwere Erdbeben in der TĂŒrkei und Syrien. Die höchsten IntensitĂ€ten wurden entlang eines etwa 200 km langen Abschnitts der Ostanatolischen Verwerfung zwischen Malatya und Iskenderun beobachtet (Mw7.8), sowie entlang einer zweiten Störung sĂŒdlich von Elbistan (Mw7.5). Basierend auf Beobachtungen (Vielzahl eingestĂŒrzter GebĂ€ude und Todesopfer) wurden IntensitĂ€ten von ĂŒber IX geschĂ€tzt. Eine Vielzahl von Nachbeben hat zusĂ€tzlich die SchĂ€den erhöht und die gesamte IntensitĂ€t weiter gesteigert. VorgeschĂ€digte GebĂ€ude durch das Hauptbeben konnten auch in Folge schwĂ€cherer Nachbeben einstĂŒrzen. Opfer und SchĂ€den wurden auch weiter entfernt vom Epizentrum gemeldet. Die Opferzahlen in Folge des zweiten Bebens fallen geringer aus, da sich viele Menschen zu diesem Zeitpunkt nicht mehr in ihren HĂ€usern aufhielten und seltener zu Schaden kamen. Jedoch ist davon auszugehen, dass das zweite Beben besonders zur Steigerung der SchĂ€den beigetragen hat. Schnelle SchadenschĂ€tzungen des CATDAT-Modells von CEDIM/Risklayer schĂ€tzen die möglichen zu erwartenden Todesopfer mit einer Bandbreite von 11.800 bis 67.010 ab. Das Modell rechtet mit einem Gesamtschaden (einschlieĂlich GebĂ€ude und Infrastruktur), der die USD 10 Mrd. ĂŒbersteigen wird. Betrachten man das Ereignis im historischen Kontext, geht die CEDIM FDA Task Force davon aus, dass es nach aktuellem Stand zu den 20 tödlichsten Erdbeben (weltweit seit 1900) gehören wird (Stand: 8. Feb. 2023). ZusĂ€tzlich leiden die Menschen vor Ort unter den niedrigen Temperaturen im Frostbereich, die auch die HilfsmaĂnahmen zusĂ€tzlich erschweren
Review article: Natural hazard risk assessments at the global scale
Since 1990, natural hazards have led to over 1.6 million fatalities globally, and economic losses are estimated at an average of around $260â310 billion per year. The scientific and policy community recognise the need to reduce these risks. As a result, the last decade has seen a rapid development of global models for assessing risk from natural hazards at the global scale. In this paper, we review the scientific literature on natural hazard risk assessments at the global scale, and specifically examine whether and how they have examined future projections of hazard, exposure, and/or vulnerability. In doing so, we examine similarities and differences between the approaches taken across the different hazards, and identify potential ways in which different hazard communities can learn from each other. For example, we show that global risk studies focusing on hydrological, climatological, and meteorological hazards, have included future projections and disaster risk reduction measures (in the case of floods), whilst these are missing in global studies related to geological hazards. The methods used for projecting future exposure in the former could be applied to the geological studies. On the other hand, studies of earthquake and tsunami risk are now using stochastic modelling approaches to allow for a fully probabilistic assessment of risk, which could benefit the modelling of risk from other hazards. Finally, we discuss opportunities for learning from methods and approaches being developed and applied to assess natural hazard risks at more continental or regional scales. Through this paper, we hope to encourage dialogue on knowledge sharing between scientists and communities working on different hazards and at different spatial scales
Natural hazard risk assessments at the global scale
Since 1990, natural hazards have led to over 1.6 million fatalities globally, and economic losses are estimated at an average of around USDâ260â310 billion per year. The scientific and policy communities recognise the need to reduce these risks. As a result, the last decade has seen a rapid development of global models for assessing risk from natural hazards at the global scale. In this paper, we review the scientific literature on natural hazard risk assessments at the global scale, and we specifically examine whether and how they have examined future projections of hazard, exposure, and/or vulnerability. In doing so, we examine similarities and differences between the approaches taken across the different hazards, and we identify potential ways in which different hazard communities can learn from each other. For example, there are a number of global risk studies focusing on hydrological, climatological, and meteorological hazards that have included future projections and disaster risk reduction measures (in the case of floods), whereas fewer exist in the peer-reviewed literature for global studies related to geological hazards. On the other hand, studies of earthquake and tsunami risk are now using stochastic modelling approaches to allow for a fully probabilistic assessment of risk, which could benefit the modelling of risk from other hazards. Finally, we discuss opportunities for learning from methods and approaches being developed and applied to assess natural hazard risks at more continental or regional scales. Through this paper, we hope to encourage further dialogue on knowledge sharing between disciplines and communities working on different hazards and risk and at different spatial scales
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