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.

Definition

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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SAM Satellite

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Launch date:
23/07/1972

News

UN-SPIDER / ZFL Regional Virtual Expert Meeting for Southern Africa

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To continue efforts to promote the use of space technologies in disaster risk management, emergency response and recovery efforts, UN-SPIDER and the Centre for Remote Sensing of Land Surfaces of the University of Bonn (ZFL) joined forces to organize the UN-SPIDER / ZFL Regional Virtual Expert Meeting for Southern Africa "Space-based Solutions for Disaster Risk Management and Emergency Response" from 13 to 15 July 2021. This regional expert meeting contributed to the efforts conducted by UN-SPIDER on disaster risk reduction, preparedness, early warning systems, disaster response... read more

Publishing date: 20/07/2021
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In Guatemala there are two volcanoes which have been more active recently: Fuego and Pacaya. These volcanoes pose a prominent threat to the lives of the inhabitants of the highly populated surrounding areas. This threat is evidenced by the 2018 eruption of Fuego, which caused the deaths of nearly 200 people, and the recent activity of Pacaya volcano since the beginning of the year, that has impacted communities located in its foothills, and which forced authorities to close Guatemala's international airport in Guatemala City due to ash fall from its activity.

The two volcanoes were effusive and explosive in early February 2021, according to reports by the Smithsonian Institute Global Volcanism Program and the National Institute of Seismology, Meteorology and Hydrology (INSIVUMEH) of Guatemala. This has resulted in... read more

Publishing date: 14/05/2021
Webinar on the Use of Satellite Technologies in Disaster Risk Management Research (INDECI & CONIDA)

Like many countries in Latin America, Peru is exposed to a variety of natural hazards that have triggered disasters in previous decades.   Disaster preparedness, response and recovery efforts are coordinated by the National Civil Defense Institute (INDECI).   In recent years, INDECI has benefited from the advisory support provided by Peru’s National Commission for Aerospace Research and Development (CONIDA).  Taking advantage of this advisory support, INDECI developed and launched at the end of 2018 its Agenda for Applied Research for the period between 2018 and 2021, addressing the preparedness, risk, and recovery phases of disaster management. More information on this agenda is available here

The research agenda recognizes the usefulness of applied... read more

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In recent years, the frequency and severity of natural hazards has increased dramatically. This development has escalated the risk of disasters and their devastating impact on the environment and communities around the world. Earth observation (EO) data has the potential to mitigate the risks of disasters and support all phases of the disaster management cycle. The international community has created various mechanisms to facilitate the use of EO data for disaster management, such as the International Charter Space and Major Disasters. The Algerian Space Agency (ASAL) has provided EO data to the International Charter for almost two decades.

The International Charter refers to a consortium of space agencies, national and regional disaster monitoring organizations that utilize EO data for... read more

Publishing date: 13/04/2021
Regional Support Offices mentioned:
Sign warning of volcanic activity in Ecuador. Image: DLR (CC-BY 3.0).

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Publishing date: 17/03/2021

Data Source

Copernicus Open Access Hub. Image Credit: ESA.
Publishing institution: European Space Agency (ESA)
The Copernicus Open Access Hub provides complete, free and open access to Sentinel missions data.

Event

Banner for FRINGE 2021. Image: ESA.

The European Space Agency is organising the 11th International Workshop on “Advances in the Science and Applications of SAR Interferometry and Sentinel-1 InSAR”, Fringe 2021.

Format

Fringe 2021 is organised around:

  • Papers and e-posters selected by the Scientific Committee;
  • Invited papers on ESA-funded studies and Sentinel-1 and future ESA SAR mission status reports;
  • Round-table discussions with seed questions prepared by the session chairpersons and ESA.

The event will take place from 31 May - June 4 2021. No participation fees will be charged.

Objectives

  • To bring together the global InSAR research and development communities and facilitate international exchange between researchers and research groups; 
  • To present the Sentinel-1 mission status, algorithms and products;
  • To review and assess the progress according to the recommendations voiced at FRINGE... read more

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