About Theistareykir
Theistareykir is a shield rising to 563 meters (1,847 feet) in Iceland's Atlantic Ocean Volcanic Regions. Its last known eruption dates to 900 BCE, in prehistoric times. The volcano has produced 3 recorded eruptions.
Geography & Climate
Theistareykir is located in Iceland, within the Iceland Neovolcanic Rift Volcanic Province of the broader Atlantic Ocean Volcanic Regions. Situated at 65.88° N, 16.97° W in the Northern Hemisphere, the volcano lies within a subarctic climate zone. With a summit elevation of 563 meters above sea level, Theistareykir is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a shield, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Theistareykir is situated along a rift zone, where tectonic plates are pulling apart. As the crust thins and fractures, magma rises to fill the gap, creating volcanic activity. Rift volcanism typically produces more fluid lava flows rather than explosive blasts, which means communities near Theistareykir in Iceland generally face slower-moving hazards like lava flows and ground fissures rather than sudden pyroclastic events. However, rift volcanoes can still generate significant ash emissions and gas releases that affect local air quality. The dominant rock type is basalt / picro-basalt, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.
Eruption History Summary
Theistareykir has 3 recorded eruptions in the geological database, spanning from 9500 BCE to 900 BCE. These eruptions span roughly 8,600 years of volcanic history.
GVP Reference Summary
The Holocene Theistareykir fissure system, including the basaltic Theistareykjarbunga shield volcano, extends from north of Myvatn lake to the coast of Iceland. This is the northernmost subaerial volcanic system along the Eastern Volcanic Zone of Iceland. The 30 km3 Theistareykjarbunga shield volcano formed slightly after deglaciation; the youngest dated eruption produced the Theistareykjahraun lava flow about 2,400 years ago.
— Smithsonian Institution, Global Volcanism Program
3 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 900 BCE | 0 | Confirmed Eruption | Storihver (Theistareykjahraun) |
| 6800 BCE | 0 | Confirmed Eruption | Borgarhraun and other flows |
| 9500 BCE | 0 | Confirmed Eruption | Theistareykjabunga shield volcano |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Theistareykir
Is Theistareykir an active volcano?+
Theistareykir is not currently classified as active. Its activity evidence is listed as "Eruption Dated." The last known eruption was in 900 BCE. However, no volcano is ever considered permanently extinct.
When did Theistareykir last erupt?+
The most recent recorded eruption of Theistareykir occurred in 900 BCE with a Volcanic Explosivity Index (VEI) of 0. The eruption was classified as a "Confirmed Eruption." Theistareykir has 3 recorded eruptions in total.
How high is Theistareykir?+
Theistareykir has a summit elevation of 563 meters (1,847 feet) above sea level. At 563 meters, it is a relatively low-elevation volcano.
What type of volcano is Theistareykir?+
Theistareykir is classified as a Shield. Shield volcanoes have distinct geological characteristics that set them apart from other volcanic types.
Where is Theistareykir located?+
Theistareykir is located in Iceland, in the Atlantic Ocean Volcanic Regions. More specifically, it lies within the Iceland Neovolcanic Rift Volcanic Province. Its exact coordinates are 65.883° latitude, -16.967° longitude.
Is it safe to visit Theistareykir?+
Theistareykir can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Iceland may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
