scholarly journals Using Google Earth Images to Extract Dense Landslides Induced by Historical Earthquakes at the Southwest of Ordos, China

2021 ◽  
Vol 8 ◽  
Author(s):  
Du Peng ◽  
Xu Yueren ◽  
Tian Qinjian ◽  
Li Wenqiao
Keyword(s):  
Spatial Distribution ◽  
Source Parameters ◽  
Extended Period ◽  
Historical Earthquakes ◽  
Google Earth ◽  
Historical Documents ◽  
Historical Earthquake ◽  
Strong Earthquakes ◽  
Ordos Block ◽  
Earthquake Zone

As historical earthquake records are simple, determining the source parameters of historical strong earthquakes over an extended period is difficult. There are numerous uncertainties in the study of historical earthquakes based on limited literature records. Co-seismic landslide interpretation combined with historical documents can yield the possibility of reducing these uncertainties. The dense co-seismic landslides can be preserved for hundreds to thousands of years in Loess Plateau, North China; furthermore, there are notable attribute differences between earthquake landslides and rainfall-triggered landslides. Along the southwestern margin of the Ordos Block, only one severe earthquake has been recorded in the past 3,000 years. The records of “Sanchuan exhaustion and Qishan collapse” provide clues for an investigation of the 780 BC Qishan earthquake. In this study, combined with historical documents, current high-resolution Google Earth images were used to extract historical landslides along the southwestern of the Ordos Block. There were 6,876 landslides with a total area of 643 km2. The landslide-intensive areas were mainly distributed along the Longxian–Qishan–Mazhao Fault in the loess valley area on the northeastern side of the fault. Loess tableland and river terraces occur on the southwest side of the fault; dense landslides have not been examined due to the topographical conditions in this area. By analyzing the spatial distribution of historical earthquake damage in this region, comparing the characteristics of rainfall-triggered landslides, and combining existing dating results for bedrock collapse and loess landslides, the interpretation of dense historical landslides can be linked to the Qishan Earthquake. The interpretation results are associated with historical records. Analyses of current earthquake cases show that the distribution of dense landslides triggered by strong earthquakes can indicate the episeismic area of an earthquake. In addition, the non-integrated landslide catalog without small- and medium-scale coseismic landslides can be used to effectively determine the source parameters of historical strong earthquakes and perform quantitative evaluations. This study evaluates the focal parameters of the 780 BC Qishan earthquake based on interpretations of the spatial distribution range of historical landslides as representations of the range of the extreme earthquake zone.

Historical Earthquake Damages to Domed Structures in Istanbul

2015 ◽  
pp. 649-673 ◽  
Author(s):  
İhsan E. Bal ◽  
F. Gülten Gülay ◽  
Meltem Vatan ◽  
Eleni Smyrou
Keyword(s):  
Spatial Distribution ◽  
Seismic Hazard ◽  
Historical Earthquakes ◽  
Seismic Events ◽  
Historical Earthquake ◽  
Historical Buildings ◽  
The Past ◽  
Ottoman Architecture ◽  
Hazard Level ◽  
Earthquake Damages

This chapter discusses the domed structures in Istanbul, which are reported damaged during strong historical earthquakes. The attention is focused mostly to their domes, the most important component of the Byzantine and the Ottoman architecture. The significant shakings, together with their estimated epicenters and magnitudes, have been defined and the spatial distribution of the reported damages in the domed structures has been examined. It is underlined once more that the Historical Peninsula, which is where once Constantinople was located, has several vulnerable structures and high seismic hazard level at the same time. Certain structures are quite vulnerable to strong shakings and received significant damages multiple times. The chapter discusses the possible effects of the future seismic events on the historical buildings in Istanbul, based on the recorded damages occurred during the past seismic events.

10 July 1894 Istanbul Earthquake: Comparing Damages and Ground Motion Simulations

2021 ◽  
Author(s):  
Nesrin Yenihayat ◽  
Eser Çaktı ◽  
Karin Şeşetyan
Keyword(s):  
Ground Motion ◽  
Fault Simulation ◽  
Source Parameters ◽  
Historical Earthquakes ◽  
Corner Frequency ◽  
Simulation Approach ◽  
Ground Motion Simulations ◽  
Finite Fault ◽  
Intensity Map ◽  
Observed Damage

<p>One of the major earthquakes that resulted in intense damages in Istanbul and its neighborhoods took place on 10 July 1894. The 1894 earthquake resulted in 474 losses of life and 482 injuries. Around 21,000 dwellings were damaged, which is a number that corresponds to 1/7 of the total dwellings of the city at that time. Without any doubt, the exact loss of life was higher. Because of the censorship, the exact loss numbers remained unknown. There is still no consensus about its magnitude, epicentral location, and rupture of length. Even though the hardness of studying with historical records due to their uncertainties and discrepancies, researchers should enlighten the source parameters of the historical earthquakes to minimize the effect of future disasters especially for the cities located close to the most active fault lines as Istanbul. The main target of this study is to enlighten possible source properties of the 1894 earthquake with the help of observed damage distribution and stochastic ground motion simulations. In this paper, stochastic based ground motion scenarios will be performed for the 10 July 1894 Istanbul earthquake, using a finite fault simulation approach with a dynamic corner frequency and the results will be compared with our intensity map obtained from observed damage distributions. To do this, in the first step, obtained damage information from various sources has been presented, evaluated, and interpreted. Secondly, we prepared an intensity map associated with the 1894 earthquake based on macro-seismic information, and damage analysis and classification. For generating ground motions with a stochastic finite fault simulation approach, the EXSIM 2012 software has been used. Using EXSIM, several scenarios are modeled with different source, path, and site parameters. Initial source properties have been obtained from findings of our previous study on the simulation of the 26 September 2019 Silivri (Istanbul) earthquake with Mw 5.8. With the comparison of spatial distributions of the ground motion intensity parameters to the obtained damage and intensity maps, we estimate the optimum location and source parameters of the 1894 Earthquake.</p>

scholarly journals A large unknown historical earthquake in the Abruzzi region (Central Italy): combination of geological and historical data

1995 ◽  
Vol 38 (5-6) ◽  
Author(s):  
G. D'Addezio ◽  
F. R. Cinti ◽  
D. Pantosti
Keyword(s):  
Historical Data ◽  
Central Italy ◽  
Large Earthquake ◽  
Historical Earthquakes ◽  
Historical Record ◽  
Historical Earthquake ◽  
Recent Event ◽  
Complete Knowledge ◽  
Historical Investigation

The combination of paleoseismological and historical investigation can be used to obtain a complete knowledge of past earthquakes. In Italy the 1000 year-long record of historical earthquakes provides an opportunity to compare data from the catalogue with results from paleoseismologic investigations. Trenching results along the Ovindoli-Pezza Fault (OPF). in the Abruzzi region. showed two surface faulting events. The most recent of these events occurred after 1019 A.D. and should be reported in the Catalogue of Italian Seismicity. Nevertheless, the earthquake appears to be missed or not well located in the Catalogue. In order to define in which century a large earthquake on the OPF should have clearly left a sign in the historical record, we carried out historical investigations back to the XI century. The studies were mainly focu5ed on disclosing possible <<negative>> e vidence for the occurrence of the most recent event along the OPF. No clear records related to this event were found but on the basis of the information we obtained the occurrence of this earthquake can be constrained between 1019 A.D. and the XV century. possibly between 1019 A.D. and XIII century.

scholarly journals Low-Cost Archaeological Investigation and Rapid Mapping of Ancient Stone Tidal Weirs in the Penghu Archipelago Using Google Earth

2019 ◽  
Vol 11 (17) ◽  
pp. 4536 ◽  
Author(s):  
Lei Luo ◽  
Xinyuan Wang ◽  
Jie Liu ◽  
Wenwu Zheng ◽  
Jing Zhen ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Information System ◽  
Spatial Distribution ◽  
Low Cost ◽  
Google Earth ◽  
Gis Analysis ◽  
Archaeological Investigation ◽  
Rapid Mapping ◽  
The Taiwan Strait ◽  
Very High

This paper provides a brief history review of the use of ancient weirs in fishing on our planet, as well as a pilot study that involves investigating and mapping the coastal heritage of ancient stone tidal weirs (STWs) in the Penghu Archipelago which is located in the Taiwan Strait. The spatial distribution and morphological features of STWs across Penghu Archipelago were investigated and analyzed using very high-resolution (VHR) and freely available Google Earth (GE) imagery and geographic information system (GIS) analysis tools. A total of 539 ground-truthed STWs were identified from multiple temporal GE images, and these accounted for over 90% of the localized inventory databases. The proposed GE-based method was found to be more efficient, timely and effective compared to field and airborne surveys. This paper illustrates the utility of GE as a source of freely available VHR remote sensing imagery for archaeological surveys and heritage sustainability in coastal areas.

The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes

2011 ◽  
Vol 182 (4) ◽  
pp. 367-379 ◽  
Author(s):  
Nicola Alessandro Pino
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Southern Italy ◽  
Source Parameters ◽  
Seismic Hazard Assessment ◽  
Historical Earthquakes ◽  
Waveform Analysis ◽  
Source Characteristics ◽  
Seismic Waveform ◽  
Earthquake Source Parameters

AbstractSeismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100–120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques.In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the XXth century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) – both of which are the strongest ever recorded instrumentally in their respective countries –and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismogenic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Apennines.

scholarly journals Rapid Mapping and Annual Dynamic Evaluation of Quality of Urban Green Spaces on Google Earth Engine

2021 ◽  
Vol 10 (10) ◽  
pp. 670
Author(s):  
Qiang Chen ◽  
Cuiping Zhong ◽  
Changfeng Jing ◽  
Yuanyuan Li ◽  
Beilei Cao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Urban Area ◽  
Google Earth ◽  
Green Spaces ◽  
Dynamic Evaluation ◽  
Urban Green ◽  
Urban Green Spaces ◽  
Rapid Mapping ◽  
Google Earth Engine

In order to achieve the United Nations 2030 Sustainable Development Goals (SDGs) related to green spaces, monitoring dynamic urban green spaces (UGSs) in cities around the world is crucial. Continuous dynamic UGS mapping is challenged by large computation, time consumption, and energy consumption requirements. Therefore, a fast and automated workflow is needed to produce a high-precision UGS map. In this study, we proposed an automatic workflow to produce up-to-date UGS maps using Otsu’s algorithm, a Random Forest (RF) classifier, and the migrating training samples method in the Google Earth Engine (GEE) platform. We took the central urban area of Beijing, China, as the study area to validate this method, and we rapidly obtained an annual UGS map of the central urban area of Beijing from 2016 to 2020. The accuracy assessment results showed that the average overall accuracy (OA) and kappa coefficient (KC) were 96.47% and 94.25%, respectively. Additionally, we used six indicators to measure quality and temporal changes in the UGS spatial distribution between 2016 and 2020. In particular, we evaluated the quality of UGS using the urban greenness index (UGI) and Shannon’s diversity index (SHDI) at the pixel level. The experimental results indicate the following: (1) The UGSs in the center of Beijing increased by 48.62 km2 from 2016 to 2020, and the increase was mainly focused in Chaoyang, Fengtai, and Shijingshan Districts. (2) The average proportion of relatively high and above levels (UGI > 0.5) in six districts increased by 2.71% in the study area from 2016 to 2020, and this proportion peaked at 36.04% in 2018. However, our result revealed that the increase was non-linear during this assessment period. (3) Although there was no significant increase or decrease in SHDI values in the study area, the distribution of the SHDI displayed a noticeable fluctuation in the northwest, southwest, and northeast regions of the study area between 2016 and 2020. Furthermore, we discussed and analyzed the influence of population on the spatial distribution of UGSs. We found that three of the five cold spots were located in the east and southeast of Haidian District. Therefore, the proposed workflow could provide rapid mapping and dynamic evaluation of the quality of UGS.

scholarly journals Environmental characterization and spatial distribution of fish fauna in estuaries in the State of Pernambuco, Brazil.

2010 ◽  
Vol 38 (1) ◽  
Author(s):  
Andréa Carla Guimarães de PAIVA ◽  
Maria Elisabeth de ARAÚJO
Keyword(s):  
Spatial Distribution ◽  
Fish Fauna ◽  
Google Earth ◽  
The State ◽  
Environmental Characterization ◽  
Citharichthys Spilopterus ◽  
Distribution Of Fish

O presente estudo teve como objetivos identificar e caracterizar os principais fatores fisiográficos das áreas estuarinas em Pernambuco, assim como as ações antrópicas por elas sofridas; listar os peixes que vivem nesses estuários, atualizando as validações dos nomes científicos das espécies; e analisar a distribuição dos registros de ocorrência das espécies por estuário. Os dados para a análise dos estuários foram baseados em três trabalhos sobre áreas estuarinas em Pernambuco. As informações sobre a ictiofauna foram obtidas a partir de 25 monografias, dissertações, teses, livros e artigos científicos. Foram utilizadas imagens das áreas estuarinas obtidas através do aplicativo Google earth. Foram identificados 17 estuários em Pernambuco, onde a ictiofauna é pouco estudada. As maiores concentrações das pesquisas ocorreram no complexo estuarino de Itamaracá e no estuário do rio Formoso, porém para algumas áreas não existem informações sobre comunidade de peixes. Foram listadas 202 espécies de peixes válidas, sendo 52,5% delas associadas a recifes. Quanto à freqüência de ocorrência, Citharichthys spilopterus e Poecilia vivipara foram classificadas como muito freqüentes, enquanto Carangidae, Gerreidae, Ariidae e Haemulidae foram as famílias mais especiosas. Atualmente, as áreas estuarinas estão em acelerado processo de degradação devido aos aterros, despejos de esgotos domésticos e industriais, desenvolvimento urbano, viveiros de carcinicultura e construção/ampliação de portos em prol do crescimento econômico. Diante desse contexto, torna-se necessário que os órgãos de fomento à pesquisa em Pernambuco estimulem estudos nessas áreas para possibilitar uma pesca sustentável. Palavras-chave: Comunidade de peixes, áreas estuarinas, impactos ambientais.

scholarly journals The detection of SARS-CoV-2 in autolysed samples from an exhumed decomposed body: Implications to virus survival, genome stability and spatial distribution in tissues

2021 ◽  
Author(s):  
Mahadeshwara Prasad ◽  
Somanna Ajjamada Nachappa ◽  
Niveditha Anand ◽  
Deepika Udayawara Rudresh ◽  
Yashika Singh ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Genome Stability ◽  
Ebola Virus ◽  
Early Stage ◽  
Extended Period ◽  
Virus Genome ◽  
The Body ◽  
Rt Pcr ◽  
Viral Transport Medium ◽  
Virus Survival

AbstractHere we report for the first time the SARS-CoV-2 detection in autolysed samples from an exhumed decomposed body post-thirty six days after death. Both naso-oropharyngeal swabs and visceral samples from the lung, intestine, liver, and kidney were collected from the body exhumed post-fifteen days after burial, stored in viral transport medium and in saturated salt solution respectively. Naso-oropharyngeal swabs showed the presence of the SARS-CoV-2 genome as identified by the amplification of viral E, N, RdRP, or ORF1ab genes by RT-PCR. Subsequent examination of tissues reveal the detection of the virus genome in the intestine and liver, while no detection in the kidney and lung. These results signify the genome stability and implicate the virus survival in decomposed swab samples and in tissues and thereafter in storage solution. Further results also indicate spatial distribution of the virus in tissues during the early stage of infection in the subject with no respiratory distress. Considering the presence of cool, humid, and moist location of the exhumation, the presence of virus genome might also indicate that SARS-CoV-2 can persist for more than seven days on the surface of dead bodies similar to the Ebola virus, confirming that transmission from deceased subjects is possible for an extended period after death. These results further reaffirm the robustness of the RT-PCR aiding in the detection of viruses or their genome in decomposed samples when other methods of detection could not be useful.

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