Earthquake

Based on data from the Sentinel-1A satellite, this image shows how and where the land uplifted and sank from the 7.8-magnitude earthquake that struck Nepal on 25 April 2015. The image was generated by the German Aerospace Center (DLR) Earth Observation Center (EOC) using data acquired by Sentinel-1A before and after the earthquake event. Image: DLR/EOC.

Definition

Sudden movement of a block of the Earth’s crust along a geological fault and associated ground shaking (IRDR Glossary).

Earthquake can be defined as the shaking of earth caused by waves moving on and below the earth's surface and causing: surface faulting, tremors vibration, liquefaction, landslides, aftershocks and/or tsunamis (WHO).

 

Facts and figures

The size or magnitude of earthquakes is determined by measuring the amplitude of the seismic waves recorded on a seismograph and the distance of the seismograph from the earthquake. These are put into a formula which converts them to a magnitude, which is a measure of the energy released by the earthquake. For every unit increase in magnitude, there is roughly a thirty-fold increase in the energy released. Earthquake magnitude was traditionally measured on the Richter scale. It is often now calculated from seismic moment, which is proportional to the fault area multiplied by the average displacement on the fault (Australian Government).

There are four different types of earthquakes: tectonic, volcanic, collapse and explosion.

  • A tectonic earthquake is one that occurs when the earth's crust breaks due to geological forces on rocks and adjoining plates that cause physical and chemical changes.
  • A volcanic earthquake is any earthquake that results from tectonic forces which occur in conjunction with volcanic activity.
  • A collapse earthquake are small earthquakes in underground caverns and mines that are caused by seismic waves produced from the explosion of rock on the surface.
  • An explosion earthquake is an earthquake that is the result of the detonation of a nuclear and/or chemical device.
 

Related content

Evento

2nd Edition of World Congress on Geology & Earth Science logo. Image: Innovinc International

GeoEarth-2020 welcomes colleagues from all branches of Geosciences and from many countries in the world to participate to the second edition of thw 'World Congress on Geology and Earth Science'. The Conference will enable the sharing of best practices in Geoscience as well as exploring the role of remote sensing in monitoring Earth processes and dynamics.

The topics of the Conference include:

CSSTEAP logo. Image: CSSTEAP.

The Asia-Pacific region faces major disaster risks in the form of earthquakes and tsunamis, tropical cyclones and typhoons, landslides, flash floods, avalanches and glacial lake outburst floods (GLOFs). Due to the large ... read more

Using NASA Remote Sensing for Disaster Management

NASA remote sensing and modeling resources are useful for managing a variety of disasters - including earthquakes, tsunamis, volcanoes, floods, landslides, wildfires, and oil spills - particularly in regions with very little in situ data. This webinar covers the fundamentals and techniques of monitoring Tsunamis, Earthquakes and Volcanoes, including pre-eruption monitoring, SAR-VIEWS, volcanic ash and remote sensing resources.

 

 

Learning Objectives: 

Participants will become aware of available NASA resources for... read more

Advisory Support

As part of the technical advisory support it provides to countries worldwide, UN-SPIDER carried out an Institutional Strengthening Mission to Myanmar from 11 to 15 March 2019 upon the request of the government. This activity was jointly organized by UN-SPIDER and the United Nations Human Settlement Programme (UN-Habitat), under auspices of the Ministry of Social Welfare, Relief and Resettle­ment (MSWRR) of Myanmar. It was hosted by the Emergency Operation Centre (EOC). 

Mission dates: 11/03/2019 to 15/03/2019

At the request of, and in coordination with the National Civil Protection Office of Tunisia, UN-SPIDER is conducting a Technical Advisory Mission to Tunisia from 4 to 6 March 2020 to identify the needs of the country to fully take advantage of space-based information for disaster management. In order to discuss the use of space-based information for risk and disaster management to subsequently make recommendations on improvements, the expert team meets with key disaster management authorities in the country.

The mission is conducted with the support of experts from the Algerian Space Agency (ASAL); the Romanian Space Agency (ROSA); the United Nations Economic Commission for Africa (UNECA); the National Observatory of Athens (NOA); and an expert on the Copernicus Emergency Management Service. The mission team is also benefiting from the support of the Chief of Space Applications of the United Nations Office for Outer Space Affairs.

As part of the mission, the team of experts will visit several institutions including the National Office of Civil Protection; the Directorate General for Forests of the Ministry of Agriculture; the Faculty of Sciences of Tunis, University of Tunis El Manar; the National Agronomic Institute of Tunisia; the National Institute of Meteorology; as well as at the Ministry of Local Affairs and Environment. Meetings will also be conducted with representatives of the National Cartographic and Remote Sensing Centre of Tunisia and other organizations. In addition, the TAM team will meet the United Nations Country Team in Tunisia, which supports disaster management efforts in the country.

During the TAM, a workshop with over 20 participants from nine institutions will take place in order to present the UN-SPIDER programme to Tunisian counterparts involved in disaster management, and encourage inter-institutional cooperation and sharing of geospatial information among them.

UN-SPIDER aims at ensuring all countries have the capacity to use all types of space-based information to support risk and disaster management efforts. To make sure that all interested stakeholders can benefit from this information in the most effective way possible, UN-SPIDER provides Technical Advisory Support to Member States through missions such as this one.

The Algerian Space Agency (ASAL), the Romanian Space Agency (ROSA) and the National Observatory of Athens (NOA) are UN-SPIDER Regional Support Office.

Mission dates: 04/03/2020 to 06/03/2020

As part of the technical advisory support it provides to countries worldwide, UN-SPIDER carried out an Institutional Strengthening Mission to Nepal from 17 to 21 December 2018 upon the request of the government. The mission was a follow-up activity to the Technical Advisory Mission (TAM) to Nepal in July 2017 that assessed use of space-derived information in all aspects of disaster management and offered recommendations and action plan to strengthen the disaster risk management and emergency response in the country. The TAM and ISM were conducted with support from the Ministry of Home Affairs (MoHA). The Nepal GIS Society also offered support in organizing the programme.

Mission dates: 17/12/2018 to 21/12/2018

Recommended Practices

On 12 November 2017 a 7.3 magnitude earthquake struck close to the town of Sarpol-e-Zahab in the Kermanshah province of the Islamic Republic of Iran. The earthquake ranked as the strongest of 2017 and among the deadliest for the decade, killing over 600 people. Fatalities were spread across the border province and destruction of local infrastructure, healthcare centers and emergency services made response harder. This Recommended Practice will outline the process for obtaining and processing SAR data before and after the 2017 earthquake for the purpose of creating actionable and helpful maps...

Data Source

Publishing institution: Airbus Defence & Space
OneAtlas is a collaborative environment to easily access very high resolution imagery, perform large-scale image processing, extract industry specific insights and benefit from Airbus assets to develop solutions. The services include infrastructure change detection, vehicle detection & counting and will soon cover aircraft detection and land use change detection as well . Airbus provides the services through a buy-what-you-need option. It is possible to test the functionalities with a 30-days Free Trial.

Noticias

Rice paddies in Rwanda. Image: A'Melody Lee / World Bank.

Release earlier this year at the Global Platform on Disaster Risk Reduction 2019, the Africa Earthquake Model paints a complete picture of earthquake risk to the continent in terms of damage to buildings and direct human and economic losses. The model lays out the African portion of the Global Earthquake Model (GEM) Foundation global maps released in December 2018. 

The model is a comprehensive resource for risk assessment as it can be overlayed with optical and radar data from space-based platforms to find recent infrastructure development in high-risk areas... read more

Publishing date: 14/10/2019
This map shows the ground motion during the six months following the earthquake that struck the Indonesian Island of Sulawesi on 28 September 2018, and was obtained by processing Copernicus Sentinel-1 images acquired between October 2018 and April 2019. Image: ESA/contains Copernicus Sentinel data (2018–19), processed by Planetek Rheticus Service.

In September 2018, the Indonesian island of Sulawesi was hit by a 7.5 magnitude earthquake. The impact, combined with the tsunami, landslides, and soil liquefaction that followed, “... claimed well over 2000 lives, destroyed homes, buildings, infrastructure and farmland in several districts,” according to the European Space Agency (ESA)

Ten months later, response efforts are now moving into the... read more

Publishing date: 06/08/2019

Pages

Hazard group

Terms in the same hazard group

Zircon - This is a contributing Drupal Theme
Design by WeebPal.