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

SAM Satellite

TerraSAR-X is a German Earth-observation satellite. Its primary payload is an X-band radar sensor with a range of different modes of operation, allowing it to record images with different swath widths, resolutions and polarisations. TerraSAR-X thus offers space-based observation capabilities that were previously unavailable. The objective of the mission is to provide value-added SAR (Synthetic Aperture Radar)... read more

Launch date:
15/06/2007

KOMPSAT-2 (Korea Multi-Purpose Satellite-2), also referred to as Arirang-2 by South Korea, has been developed by KARI (Korea Aerospace Research Institute) to continue the observation program of the KOMPSAT-1 mission.

The main mission objectives of the KOMPSAT-2 system are to provide a surveillance of large scale disasters and its countermeasure, acquisition of independent high resolution images for GIS (Geographic Information Systems), composition of printed maps and digitized maps for domestic and overseas territories, balanced development of Korean territories, survey of natural resources, and continuation of satellite... read more

Launch date:
28/07/2006

ALOS (Advanced Land Observation Satellite) has been decommissioned. ALOS was successfully launched on January 24, 2006 from the Tanegashima Space Center.

ALOS was one of the world's largest earth observation satellites whose function is to collect global and high resolution land observation data. ALOS data was made available at conditions similar to those of ERS and Envisat missions, namely for scientific 'Category-1' use as well as commercial applications.

The ALOS (renamed "Daichi")... read more

Launch date:
24/01/2006

Cartosat-1 satellite sensor was built by ISRO (Indian Space Research Organization) which is mainly intended for cartographic applications was launched by the PSLV on May 5, 2005 at Sriharikota, India.
Prior to launch, ISRO renamed the IRS-P5 spacecraft to CartoSat-1, to describe more aptly the application spectrum of its observation data. In this mission, the high resolution of the data (2.5 m GSD) is being traded at the expense... read more

Launch date:
05/05/2005

IRS-P6 is an Earth observation mission within the IRS (Indian Remote-Sensing Satellite) series of ISRO (Indian Space Research Organization), Bangalore, India. The overall objectives of the IRS-P6 mission (ResourceSat-1) are to provide continued remote sensing data services on an operational basis for integrated land and water resources management. IRS-P6 is the continuation of the IRS-1C/1D missions with considerably enhanced... read more

Launch date:
17/10/2003

On 26 September 2003 Nigeria launched its $13 million national satellite NigeriaSat-1 in Plesetsk, Russia under a seven-nation constellation being handled by a Russian firm, Cosmos. Nigeriasat-1 is a low earth orbit micro satellite for disaster monitoring looking spacecraft, 5-year target design life-span orbit 700km. The launching of the National Satellite, which started development in November 2001, had been postponed from July 2003 because the Russian Space Agency had to launch a military satellite during that period. NigeriaSat-1 is one of five satellites which will make up a network called the Disaster Monitoring Constellation. The other partners in the international... read more

Launch date:
27/09/2003

BNSCSat (British National Space Centre Satellite) or UK-DMC 1 is the UK component of DMC. The Disaster Monitoring Constellation (DMC) is an international programme initially proposed in 1996 and led by SSTL (Surrey Satellite Technology Ltd) from the United Kingdom, to construct a network of five affordable Low Earth Orbit (LEO) microsatellites. The objective is to provide a daily global imaging capability at medium resolution (30-40 m), in 3-4 spectral bands, for rapid-... read more

Launch date:
27/09/2003

The satellites SPOT 5 (Satellite Probatoire de l'Observation de la Terre) was a third generation of SPOT earth observation satellite operated by Spot Image.

SPOT 5 used the improved SPOT Mk.3 bus design.

The prime imaging instrument was HRG (High Resolution Geometric), which was built by Astrium SAS of Vélizy, France to continue to improve the HRVIR service of SPOT-4. Two HRG instruments are provided in the conventional SPOT-series double-observation configuration, each with a FOV of 4.13º and the same... read more

Launch date:
04/05/2002

Terra explores the connections between Earth's atmosphere, land, snow and ice, ocean, and energy balance to understand Earth's climate and climate change and to map the impact of human activity and natural disasters on communities and ecosystems. It was launched on 18 December 1999 and has far exceeded its design life, having a strong chance of operating successfullty into the early 2020s.
Terra is in a circular sun-synchronous... read more

Launch date:
18/12/1999

The government-owned Landsat 7 was successfully launched on April 15, 1999, from the Western Test Range of Vandenberg Air Force Base, California, on a Delta-II expendable launch vehicle. The Earth observing instrument on Landsat 7, the Enhanced Thematic Mapper Plus (ETM+), replicates the capabilities of the highly successful Thematic Mapper instruments on Landsats 4 and 5.
Landsat 7 is the most accurately calibrated Earth-observing satellitei.e., its measurements are extremely accurate when compared to the same measurements made on the ground.  Landsat 7’s sensor has been called “the most stable, best characterized... read more

Launch date:
15/04/1999

Pages

Hazard group

Terms in the same hazard group

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