Global Volcanism Program | Þórðarhyrna

The Global Volcanism Program has no activity reports available for Þórðarhyrna.

The Global Volcanism Program has no Weekly Reports available for Þórðarhyrna.

The Global Volcanism Program has no Bulletin Reports available for Þórðarhyrna.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Cones

Feature Name

Feature Type

Elevation

Latitude

Longitude

Palsfjall

Cone

1335 m

64° 18' 0" N

17° 41' 0" W

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

373012

1904 CE

1,650 m / 5,413 ft

64.267°N
17.617°W

Morphology

Volcano Landform
Composite

Volcano Types
Stratovolcano

Tectonic Setting

Rift zone
Oceanic crust (< 15 km)

Geological Summary

The Þórðarhyrna central volcano has been moderately active during the Holocene, with the last eruption occurring in 1903 CE. It is the second and less active central volcano of the Grímsvötn-Laki volcanic system, located about 20 km SW of the more active Grímsvötn central volcano and connected to it by a subglacial mountain ridge. The volcano has a diameter of 15 km, and is covered by ice 100-600 m thick within the Vatnajökull glacier. The last eruption occurred in 1903 CE. The recent activity has been explosive (phreatomagmatic) basaltic eruptions with tephra volumes ranging from 0.01-1 km³, but several rhyolitic nunataks characterize this volcano. Eruptions are accompanied by jökulhlaups. Being the only second central volcano on a volcanic system with considerable historical volcanic activity, Þórðarhyrna is treated as an independent volcano although the fissure swarm events are shared with the Grímsvötn system.

References

The Global Volcanism Program has no references available for Þórðarhyrna.

Eruptive History

There is data available for 3 confirmed Holocene eruptive periods.

1902 Dec - 1904 Jan 12 Confirmed Eruption VEI: 4

Episode 1 | Eruption

Grímsvötn and Thordarhyrna

1902 Dec - 1904 Jan 12

Evidence from Observations: Reported

List of 5 Events for Episode 1 at Grímsvötn and Thordarhyrna

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Ash
- - - -	- - - -	Jokulhaup
1902 Dec	- - - -	VEI (Explosivity Index)
1903 May 28	- - - -	VEI (Explosivity Index)

1887 Aug 15 - 1889 Confirmed Eruption VEI: 2

Episode 1 | Eruption

Thordarhyrna

1887 Aug 15 - 1889

Evidence from Observations: Reported

List of 5 Events for Episode 1 at Thordarhyrna

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Ash
- - - -	- - - -	Earthquakes (undefined)
- - - -	- - - -	Jokulhaup
1887 Aug 15	- - - -	VEI (Explosivity Index)

1823 Feb 4 ± 4 days Confirmed Eruption VEI: 2

Episode 1 | Eruption

Grímsvötn-Thordarhyrna

1823 Feb 4 ± 4 days - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1 at Grímsvötn-Thordarhyrna

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Ash
1823 Feb 4 ± 4 days	- - - -	VEI (Explosivity Index)

Deformation History

There is no Deformation History data available for Þórðarhyrna.

Emission History

There is no Emissions History data available for Þórðarhyrna.

Photo Gallery

Þórðarhyrna (Thordarhyrna) is below the Vatnajökull glacier with the ice between 100-600 m thick, shown in this 29 October 2019 Sentinel-2 satellite image (N is at the top; this image is approximately 52 km across). The edifice is 15 km in diameter and is part of the Grímsvötn volcanic system. Cauldrons that have formed within the ice above indicate geothermal activity.

Satellite image courtesy of Copernicus Sentinel Data, 2019.

GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

There are no samples for Þórðarhyrna in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites

Catalogue of Icelandic Volcanoes (Link to Þórðarhyrna)

The Catalogue of Icelandic Volcanoes is an interactive, web-based tool, containing information on volcanic systems that belong to the active volcanic zones of Iceland. It is a collaboration of the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere. This official publication is intended to serve as an accurate and up-to-date source of information about active volcanoes in Iceland and their characteristics. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the effort of FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite.

Copernicus Browser

The Copernicus Browser replaced the Sentinel Hub Playground browser in 2023, to provide access to Earth observation archives from the Copernicus Data Space Ecosystem, the main distribution platform for data from the EU Copernicus missions.

MIROVA

Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.

MODVOLC Thermal Alerts

Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.

WOVOdat
   Single Volcano View
   Temporal Evolution of Unrest
   Side by Side Volcanoes

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

GVMID Data on Volcano Monitoring Infrastructure The Global Volcano Monitoring Infrastructure Database GVMID, is aimed at documenting and improving capabilities of volcano monitoring from the ground and space. GVMID should provide a snapshot and baseline view of the techniques and instrumentation that are in place at various volcanoes, which can be use by volcano observatories as reference to setup new monitoring system or improving networks at a specific volcano. These data will allow identification of what monitoring gaps exist, which can be then targeted by remote sensing infrastructure and future instrument deployments.

Volcanic Hazard Maps

The IAVCEI Commission on Volcanic Hazards and Risk has a Volcanic Hazard Maps database designed to serve as a resource for hazard mappers (or other interested parties) to explore how common issues in hazard map development have been addressed at different volcanoes, in different countries, for different hazards, and for different intended audiences. In addition to the comprehensive, searchable Volcanic Hazard Maps Database, this website contains information about diversity of volcanic hazard maps, illustrated using examples from the database. This site is for educational purposes related to volcanic hazard maps. Hazard maps found on this website should not be used for emergency purposes. For the most recent, official hazard map for a particular volcano, please seek out the proper institutional authorities on the matter.

IRIS seismic stations/networks

Incorporated Research Institutions for Seismology (IRIS) Data Services map showing the location of seismic stations from all available networks (permanent or temporary) within a radius of 0.18° (about 20 km at mid-latitudes) from the given location of Þórðarhyrna. Users can customize a variety of filters and options in the left panel. Note that if there are no stations are known the map will default to show the entire world with a "No data matched request" error notice.

UNAVCO GPS/GNSS stations

Geodetic Data Services map from UNAVCO showing the location of GPS/GNSS stations from all available networks (permanent or temporary) within a radius of 20 km from the given location of Þórðarhyrna. Users can customize the data search based on station or network names, location, and time window. Requires Adobe Flash Player.

DECADE Data

The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the Mapping Gas Emissions (MaGa) Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO₂ to the atmosphere, but installing CO₂ monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.

EarthChem

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).