Volcanic Eruption

The Operational Land Imager (OLI) on the Landsat 8 satellite acquired this top image of Mount Etna on December 28, 2018. The image highlights the active vent and thermal infrared signature from lava flows, which can be seen near the newly formed fissure on the southeastern side of the volcano. The image was created with data from OLI (bands 4-3-2) and the Thermal Infrared Sensor (TIRS) on Landsat 8. Image: NASA.


A type of volcanic event near an opening/vent in the Earth’s surface including volcanic eruptions of lava, ash, hot vapour, gas, and pyroclastic material (IRDR Glossary).

The majority of volcanoes in the world form along the boundaries of Earth's tectonic plates. When tectonic plates collide, one often plunges deep below the other in what's known as a subduction zone. Not all volcanoes are related to subduction: another way volcanoes can form is what's known as hotspot volcanism. In this situation, a zone of magmatic activity—or a hotspot—in the middle of a tectonic plate can push up through the crust to form a volcano. Although the hotspot itself is thought to be largely stationary, the tectonic plates continue their slow march, building a line of volcanoes or islands on the surface (National Geographic).

A volcano is currently active if it is erupting lava, releasing gas or generating seismic activity. An active volcano is labelled dormant if it has not erupted for a long time but could erupt again in the future. When a volcano has been dormant for more than 10 000 years, it is considered extinct. Volcanoes can remain inactive, or dormant, for hundreds or thousands of years before erupting again. During this time, they can become covered by vegetation, making them difficult to identify.

How explosive a volcanic eruption is depends on how easily magma can flow or trap gas. If magma is able to trap a large amount of gas, it can produce explosive eruptions.  (Australian Government).


Facts and figures

Over the last 11,500 years, more than 1,500 major eruptions have occurred, with approximately 500 in the Pacific "Ring of Fire" alone (PreventionWeb).

There are volcanoes on every continent, even Antarctica. Some 1,500 volcanoes are still considered potentially active around the world today; 161 of those—over 10 percent—sit within the boundaries of the United States (National Geographic).

There are different types of eruptive events. We can distinguish between primary and secondary events.

Primary events are:

  • Pyroclastic explosions
  • Hot ash releases
  • Lava flows
  • Gas emissions
  • Glowing avalanches (gas and ash releases)

Secondary events are:

  • Melting ice, snow and rain accompanying eruptions are likely to provoke floods and hot mudflows (or lahars)
  • Hot ash releases can start fires (WHO).

Volcanoes can have many different appearances. The shape of a volcano provides clues to the type and size of eruption that occurred. Eruption types and sizes depend on what the magma is made up of. Three common volcano forms are:

  1. Shield volcano: have a broad, flattened dome-like shape created by layers of hot and runny lava flowing over its surface and cooling.
  2. Composite volcano : also known as stratovolcanoes, they are formed from explosive eruptions. These eruptions create steep sided cones.
  3. Caldera volcano: these volcanoes erupt so explosively that little material builds up near the vent. Eruptions partly or entirely empty the underlying magma chamber which leaves the region around the vent unsupported, causing it to sink or collapse under its own weight. The resulting basin-shaped depression is roughly circular and is usually several kilometres or more in diameter (Australian Government).

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GP-STAR factsheet

Publishing institution: Committee on Earth Observation Satellites (CEOS)

CEOS Disasters Working Group Space agencies organised in the Committee on Earth Observation Satellites (CEOS) formed a permanent Working Group in 2013. Together with volcanologists and Remote Sensing specialists, a Volcano Pilot activity was started with the following aims:

  1. Demonstrate the utility of integrated, systematic space-based EO as a volcano monitoring tool on a regional basis and for specific case studies
  2. Provide space-based EO products to the existing operational community (such as volcano observatories and VAACs) that can be used for better understanding volcanic activity and reducing impact and risk from eruptions
  3. Build the capacity for use of EO data at the majority of the world‘s volcanoes (particularly those that are not monitored by other means)

After further specification, the main objective of the pilot activity consists of a regional study of volcanic unrest and eruptions in the Latin American volcanic arc (from... read more

Data Source

Publishing institution: European Space Agency (ESA)
The main objective of the SENTINEL-3 mission is to monitor sea and land surface temperature, sea surface topography and ocean and land surface colour with high accuracy and reliability. The high resolution data is meant to support ocean forecasting systems, environmental monitoring and climate monitoring. ESA and EUMETSAT will jointly operate the SENTINEL-3 mission and bothy institutions provide access to the processed data. Sentinel 3 carries four main instruments: the OLCI, SLSTR, Altimetry and a MWR Microwave Radiometer.


Image of the eruption and resulting ash plume of the Volcan de Fuego in Guatemala captured by the NOAA/NASA Suomi National Polar-orbiting Partnership satellite on 3 June 2018. Image: NASA Earth Observatory

Satellites from NASA and the US National Oceanic and Atmospheric Administration (NOAA) are monitoring the eruption of Volcan de Fuego (Volcano of Fire) in Guatemala that has killed at least 69 people since it started erupting on 3 June 2018.

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the joint NOAA/NASA Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite captured an imagery) of the eruption and resulting ash plume emitted by the volcano.

Such satellite images can be utilised by civil authorities, scientists and the local population to understand where pyroclastic flows, a high-density mix of hot lava blocks, pumice, ash and volcanic gas, are moving in order to avoid disaster.

Just before noon on 3 June, the Volcan de Fuego, which is located approximately 50 kilometres southwest of Guatemala City, produced an explosive eruption that sent ash billowing thousands of metres into the air. A... read more

Publishing date: 06/06/2018
Logo of the International Charter "Space and Major Disasters"

The International Charter “Space and Major Disasters” has been activated for Guatemala’s Fuego volcano on 5 June.

Guatemala’s most powerful eruption in 100 years has killed at least 69 people with many more missing, according to local reports.

A state of emergency has been declared with the eruption, which started on Sunday, cascaded vast clouds of volcanic ash, rocks and toxic gas into the atmosphere. 3,000 local residents have been evacuated into temporary shelters as pyroclastic flows threaten to engulf villages surrounding the volcano.

Fuego is situated 40km south-west of the capital Guatemala City and the eruption closed the city’s La Aurora International Airport as the clouds of volcanic ash and gases rose 10 km into the air.

Emergency responders are working alongside soldiers and firefighters to search for missing people in the dense covering of ash, mud and volcanic rock.

The... read more

Publishing date: 05/06/2018
An image of the Sheveluch (Shiveluch) volcano in Kamchatka, Russian Federation emitting an ash plume taken by NASA’s Aqua satellite in 2012. Image: NASA Earth Observatory.

Significant activity from volcanoes in the Russian Federation have been observed from space in recent months. The Kamchatka and Kuril Islands volcanoes, located in the fact east of the country, are being monitored by satellites in order to avert the hazards caused by their regular eruptions to air travel and to local populations.

These volcanoes are among the most active in the world, generally erupting between three and seven times every year. As of 4 May 2018, two volcanoes in Kamchatka - Karymysky and Sheveluch - are subject to an orange aviation colour code meaning that a volcano is exhibiting heightened unrest with increased likelihood of eruption or that a volcanic eruption is underway with no or minor ash emission. The Ebeko volcano located in the Kuril Islands is also subject to the same warning.

When volcanoes in the region erupt, they... read more

Publishing date: 16/05/2018
An image acquired 6 May 2018 via NASA’s Terra satellite picks up hotspots on the thermal infrared bands – shown in yellow. These hotspots are newly formed fissures and lava flows. Image: NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team.
NASA satellites are closely monitoring Kilauea volcano in Hawaii, United States of America amid fears that the ongoing eruption could cause further evacuation of the local population.
On 30 April 2018, the floor of Kilauea’s crater began to collapse. Earthquakes followed, including one that measured magnitude 6.9, and lava was pushed into new underground areas that eventually broke through the ground in areas such as Leilani Estates. The fissures and high levels of sulphur dioxide gas prompted the authorities to order nearly 2,000 residents to evacuate Lanipuna Gardens and the neighbouring Leilani... read more
Publishing date: 13/05/2018
Lava flows erupting from a fissure on 5/5/18. Image: US Geological Survey.

The International Charter Space and Major Disasters has been activated for an earthquake and eruption of the Kilauea Volcano in Hawaii, USA on Monday.

The volcano erupted on 4 May alongside a 6.9 magnitude earthquake, spraying lava up to 70 metres and causing the evacuation of 2000 individuals, in addition to the destruction of several buildings. Dangerous levels of toxic sulfur dioxide from the lava flows also present a hazard. Residents are urged not to return to hazardous areas until the risk has subsided.

This activation was requested by the US Geological Survey on behalf of USGS Hawaii Volcano Observatory/Cascades Volcano Observatory. This project was also managed by the USGS.

Publishing date: 11/05/2018


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