Katla

Photo of this volcano
Google Earth icon
Google Earth Placemark
  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 63.63°N
  • 19.05°W

  • 1512 m
    4959 ft

  • 372030
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

12 October-18 October 2011

The Iceland Met Office reported increased seismic activity within Katla's caldera. Unrest was first noted in July, when a short-lived glacial flood burst from the Myrdalsjökull glacier that covers Katla occurred in connection with increased seismicity. Since then, several hundred micro-earthquakes had taken place within the area of the caldera. On 5 October an intense earthquake swarm was detected. Most of the earthquakes originated at 5 km depth; the largest one was approximately a M 3.7.

Source: Icelandic Met Office



 Available Weekly Reports


2011: July | October


12 October-18 October 2011

The Iceland Met Office reported increased seismic activity within Katla's caldera. Unrest was first noted in July, when a short-lived glacial flood burst from the Myrdalsjökull glacier that covers Katla occurred in connection with increased seismicity. Since then, several hundred micro-earthquakes had taken place within the area of the caldera. On 5 October an intense earthquake swarm was detected. Most of the earthquakes originated at 5 km depth; the largest one was approximately a M 3.7.

Source: Icelandic Met Office


6 July-12 July 2011

The Iceland Met Office and news sources reported that on 9 July a jökulhlaup from Myrdalsjökull, the ice sheet that covers Katla, originated from three ice cauldrons in the SE part of the caldera. During previous weeks microseismicity had been registered near several of the ice cauldrons. Around the time of peak harmonic tremor, in the early evening on 8 July, the Myrdalsjökull flood monitoring system indicated increased conduction. The water level reached the bridge around midnight and damaged the sensors. According to news articles, one new cauldron that had formed, along with cracks in the glacier around the cauldrons, may have been caused by a small eruption at Katla although no evidence of an eruption was observed. The jökulhlaup had destroyed a 128-m-long bridge and caused damage, resulting in the closing of part of the Ring Road. About 200 people were evacuated from the area but allowed to return home later that day. On 10 July the water had subsided and returned to normal levels.

Sources: Icelandic Met Office, Morgunbladid News, Iceland Review, Iceland Review, Iceland Review


Summary of eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1999 Jul 17 (?) ] [ 1999 Aug 15 ± 5 days ] Uncertain 0   W, S, and E margins of caldera
[ 1955 Jun 25 ] [ Unknown ] Uncertain 0   East side of caldera
1918 Oct 12 1918 Nov 4 Confirmed 4 Historical Observations South side of caldera, K-1918
1860 May 8 1860 May 27 Confirmed 4 Historical Observations
1823 Jun 26 1823 Jul 23 Confirmed 3 Historical Observations Arcuate fissure in south part of caldera
1755 Oct 17 1756 Feb 13 Confirmed 5 Historical Observations E-W fissure in center of caldera
1721 May 11 1721 Oct 15 ± 45 days Confirmed 5 Historical Observations
1660 Nov 3 1661 Confirmed 4 Historical Observations
1625 Sep 2 1625 Sep 14 Confirmed 5 Historical Observations
1612 Oct 12 Unknown Confirmed 4 Historical Observations
1580 Aug 11 Unknown Confirmed 4 Historical Observations
1550 (?) Unknown Confirmed 4 Tephrochronology
1500 (?) Unknown Confirmed 4 Tephrochronology
1450 ± 50 years Unknown Confirmed   Tephrochronology
1440 Unknown Confirmed 4 Historical Observations
1416 Unknown Confirmed 4 Historical Observations
1357 ± 3 years Unknown Confirmed 4 Historical Observations SW of Kotlugja
1311 Jan 18 Unknown Confirmed   Historical Observations
1262 Unknown Confirmed 5 Historical Observations
1245 Unknown Confirmed 4 Historical Observations
1210 (?) Unknown Confirmed 4 Tephrochronology
1177 ± 2 years Unknown Confirmed 3 Historical Observations
1150 ± 50 years Unknown Confirmed   Tephrochronology
[ 1000 (?) ] [ Unknown ] Discredited    
0960 (?) Unknown Confirmed 3 Tephrochronology
0950 (?) Unknown Confirmed   Tephrochronology
0934 ± 2 years 0940 (?) Confirmed 4 Ice Core Eldgjá fissure system (NE flank)
0920 Unknown Confirmed 4 Historical Observations
[ 0904 (?) ] [ Unknown ] Uncertain    
0820 (?) Unknown Confirmed   Tephrochronology
0780 (?) Unknown Confirmed   Tephrochronology
0680 (?) Unknown Confirmed   Tephrochronology
0610 (?) Unknown Confirmed   Tephrochronology
0590 (?) Unknown Confirmed   Tephrochronology
0540 (?) Unknown Confirmed   Tephrochronology
0500 (?) Unknown Confirmed   Tephrochronology
0400 (?) Unknown Confirmed   Tephrochronology
0290 (?) Unknown Confirmed   Tephrochronology
0270 ± 12 years Unknown Confirmed 3 Radiocarbon (uncorrected) Tephra layer YN
0260 (?) Unknown Confirmed   Tephrochronology
0200 (?) Unknown Confirmed   Tephrochronology
0130 (?) Unknown Confirmed   Tephrochronology
0030 (?) Unknown Confirmed   Tephrochronology
0080 BCE (?) Unknown Confirmed   Tephrochronology
0250 BCE (?) Unknown Confirmed   Tephrochronology
0370 BCE (?) Unknown Confirmed   Tephrochronology
0430 BCE (?) Unknown Confirmed   Tephrochronology
0530 BCE (?) Unknown Confirmed   Tephrochronology
0550 BCE (?) Unknown Confirmed   Tephrochronology
0560 BCE (?) Unknown Confirmed   Tephrochronology
0600 BCE (?) Unknown Confirmed   Tephrochronology
0650 BCE (?) Unknown Confirmed   Tephrochronology
0700 BCE (?) Unknown Confirmed   Tephrochronology
0740 BCE (?) Unknown Confirmed   Tephrochronology
0780 BCE (?) Unknown Confirmed   Tephrochronology
0850 BCE ± 50 years Unknown Confirmed 4 Radiocarbon (corrected) Tephra layer UN
0860 BCE (?) Unknown Confirmed   Tephrochronology
0920 BCE (?) Unknown Confirmed   Tephrochronology
0990 BCE (?) Unknown Confirmed   Tephrochronology
1160 BCE (?) Unknown Confirmed   Tephrochronology
1190 BCE (?) Unknown Confirmed   Tephrochronology
1220 BCE ± 12 years Unknown Confirmed 3 Radiocarbon (corrected) Tephra layer MN
1280 BCE (?) Unknown Confirmed   Tephrochronology
1290 BCE (?) Unknown Confirmed   Tephrochronology
1440 BCE ± 40 years Unknown Confirmed 4 Radiocarbon (corrected) Tephra layer LN
1540 BCE (?) Unknown Confirmed   Tephrochronology
1640 BCE (?) Unknown Confirmed   Tephrochronology
1670 BCE (?) Unknown Confirmed   Tephrochronology
1700 BCE (?) Unknown Confirmed   Tephrochronology
1850 BCE (?) Unknown Confirmed   Tephrochronology
1910 BCE (?) Unknown Confirmed   Tephrochronology
1920 BCE (?) Unknown Confirmed 4 Radiocarbon (corrected) Tephra layer N4
1950 BCE (?) Unknown Confirmed   Tephrochronology
2000 BCE (?) Unknown Confirmed   Tephrochronology
2020 BCE (?) Unknown Confirmed   Tephrochronology
2050 BCE (?) Unknown Confirmed   Tephrochronology
2110 BCE (?) Unknown Confirmed   Tephrochronology
2160 BCE (?) Unknown Confirmed   Tephrochronology
2190 BCE (?) Unknown Confirmed   Tephrochronology
2220 BCE (?) Unknown Confirmed   Tephrochronology
2250 BCE (?) Unknown Confirmed   Tephrochronology
2420 BCE (?) Unknown Confirmed   Tephrochronology
2480 BCE (?) Unknown Confirmed   Tephrochronology
2540 BCE (?) Unknown Confirmed   Tephrochronology
2680 BCE (?) Unknown Confirmed   Tephrochronology
2850 BCE (?) Unknown Confirmed   Tephrochronology
2920 BCE (?) Unknown Confirmed 3 Tephrochronology Tephra layer N2
3180 BCE (?) Unknown Confirmed   Tephrochronology
3280 BCE (?) Unknown Confirmed   Tephrochronology
3370 BCE (?) Unknown Confirmed   Tephrochronology
3390 BCE (?) Unknown Confirmed   Tephrochronology
3480 BCE (?) Unknown Confirmed   Tephrochronology
3510 BCE (?) Unknown Confirmed   Tephrochronology
3640 BCE (?) Unknown Confirmed   Tephrochronology
3670 BCE (?) Unknown Confirmed   Tephrochronology
3720 BCE (?) Unknown Confirmed   Tephrochronology
3790 BCE (?) Unknown Confirmed   Tephrochronology Tephra layer N1
3810 BCE (?) Unknown Confirmed   Tephrochronology Tephra layer A1
3930 BCE (?) Unknown Confirmed   Tephrochronology
4060 BCE (?) Unknown Confirmed   Tephrochronology
4210 BCE (?) Unknown Confirmed   Tephrochronology
4240 BCE (?) Unknown Confirmed   Tephrochronology
4280 BCE (?) Unknown Confirmed   Tephrochronology
4370 BCE (?) Unknown Confirmed   Tephrochronology
4430 BCE (?) Unknown Confirmed   Tephrochronology
4610 BCE (?) Unknown Confirmed   Tephrochronology
4660 BCE (?) Unknown Confirmed   Tephrochronology
4750 BCE (?) Unknown Confirmed   Tephrochronology
4810 BCE (?) Unknown Confirmed   Tephrochronology
4880 BCE (?) Unknown Confirmed   Tephrochronology
5020 BCE (?) Unknown Confirmed   Tephrochronology
5040 BCE (?) Unknown Confirmed   Tephrochronology
5070 BCE (?) Unknown Confirmed   Tephrochronology
5180 BCE (?) Unknown Confirmed   Tephrochronology Tephra layer A7
5230 BCE (?) Unknown Confirmed   Tephrochronology
5360 BCE (?) Unknown Confirmed   Tephrochronology
5460 BCE (?) Unknown Confirmed   Tephrochronology Tephra layer A8
5470 BCE (?) Unknown Confirmed   Tephrochronology
5550 BCE (?) Unknown Confirmed   Tephrochronology NE flank
5560 BCE (?) Unknown Confirmed   Tephrochronology Tephra layer A9
5630 BCE (?) Unknown Confirmed   Tephrochronology
5710 BCE (?) Unknown Confirmed   Tephrochronology
5720 BCE (?) Unknown Confirmed   Tephrochronology
5730 BCE (?) Unknown Confirmed   Tephrochronology
5850 BCE (?) Unknown Confirmed   Tephrochronology
5890 BCE (?) Unknown Confirmed   Tephrochronology
5960 BCE (?) Unknown Confirmed   Tephrochronology
6050 BCE (?) Unknown Confirmed   Tephrochronology
6170 BCE (?) Unknown Confirmed   Tephrochronology
6200 BCE (?) Unknown Confirmed   Tephrochronology
6230 BCE (?) Unknown Confirmed   Tephrochronology
6380 BCE (?) Unknown Confirmed   Tephrochronology

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Bjornsson H, Palsson F, Gudmundsson M T, 2000. Surface and bedrock topography of the Myrdalsjokull ice cap, Iceland: the Katla caldera, eruptions sites and routes of jokulhlaups. Jokull, 49: 29-46.

Einarsson E H, Larsen G, Thorarinsson S, 1980. The Solheimar tephra layer and the Katla eruption of ca. 1357. Acta Nat Islandica, 3: 1-24.

Gudmundsson A T, 1986b. Iceland-Fires. Reykjavik: Vaka-Helgafell, 168 p.

Jakobsson S P, 1979. Petrology of recent basalts of the eastern volcanic zone, Iceland. Acta Nat Islandica, 26: 1-103.

Johannesson H, Jakobsson S P, Saemundsson K, 1982. Geological map of Iceland, sheet 6, south Iceland. Icelandic Museum Nat Hist & Iceland Geodetic Surv, 1:250,000 geol map, 2nd edition.

Johannesson H, Saemundsson K, 1998. Geological map of Iceland, 1:500,000. Tectonics. Icelandic Inst Nat Hist, Reykjavik.

Jonsson J, 1987. The Eldgjar eruption and the Landbrot lava. Natturufraedingurinn, 57: 1-20 (in Icelandic with English summary).

Lacasse C, Garbe-Schonberg C-D, 2001. Explosive silicic volcanism in Iceland and the Jan Mayen area during the last 6 Ma: sources and timing of major eruptions. J Volc Geotherm Res, 107: 113-147.

Lacasse C, Sigurdsson H, Carey S N, Johannesson H, Thomas L E, Rogers N W, 2007. Bimodal volcanism at the Katla subglacial caldera, Iceland: insight into the geochemistry and petrogenesis of rhyolitic magmas. Bull Volc, 69: 373-399.

Lacasse C, Sigurdsson H, Johannesson H, Paterne M, Carey S, 1995. Source of Ash Zone 1 in the North Atlantic. Bull Volc, 57: 18-32.

Larsen G, 2000. Holocene eruptions within the Katla volcanic system, south Iceland: characteristics and environmental impact. Jokull, 49: 1-28.

Larsen G, 1979. The age of Eldgja lavas. Natturufraedingurinn, 49: 1-26 (in Icelandic with English summary).

Larsen G, Newton A J, Dugmore A J, Vilmundardottir E G, 2001. Geochemistry, dispersal, volumes and chronology of Holocene silicic tephra layers from the Katla volcanic system, Iceland. J Quat Sci, 16: 119-132.

Newhall C G, Dzurisin D, 1988. Historical unrest at large calderas of the world. U S Geol Surv Bull, 1855: 1108 p, 2 vol.

Oladottir B A, Larsen G, Thordarson T, Sigmarsson O, 2005. The Katla volcano S-Iceland: Holocene tephra stratigraphy and eruption frequency. Jokull, 55: 53-74.

Oladottir B A, Sigmarsson O, Larsen G, Thordarson T, 2008. Katla volcano, Iceland: magma composition, dynamics and eruption frequency as recorded by Holocene tephra layers. Bull Volc, 70: 475-493.

Scharrer K, Spieler O, Mayer C, Munzer U, 2008. Imprints of sub-glacial volcanic activity on a glacier surface--SAR study of Katla volcano, Iceland. Bull Volc, 70: 495-506.

Soosalu H, Jonsdottir K, Einarsson P, 2006. Seismicity crisis at the Katla volcano, Iceland--signs of a cryptodome?. J Volc Geotherm Res, 153: 177-186.

Steinthorsson S, et al., 2002. Catalog of Active Volcanoes of the World - Iceland. Unpublished manuscript.

Thorarinsson S, 1975. Katla and the annal of Katla eruptions. Arbok Ferdafelags Islands 1975, p 125-149.

Thordarson T, Hoskuldsson A, 2008. Postglacial eruptions in Iceland. Jokull, 58: 197-228.

Thordarson T, Miller D J, Larsen G, Self S, Sigurdsson H, 2001. New estimates of sulfur degassing and atmospheric mass-loading by the 934 AD Eldgja eruption. J Volc Geotherm Res, 107: 33-54.

Katla volcano, located near the southern end of Iceland's eastern volcanic zone, is hidden beneath the Myrdalsjökull icecap. The subglacial basaltic-to-rhyolitic volcano is one of Iceland's most active and is a frequent producer of damaging jökulhlaups, or glacier-outburst floods. A large 10 x 14 km subglacial caldera with a long axis in a NW-SE direction is up to 750 m deep. Its high point reaches 1380 m, and three major outlet glaciers have breached its rim. Although most historical eruptions have taken place from fissures inside the caldera, the Eldgjá fissure system, which extends about 60 km to the NE from the current ice margin towards Grímsvötn volcano, has been the source of major Holocene eruptions. An eruption from the Eldgjá fissure system about 934 CE produced a voluminous lava flow of about 18 cu km, one of the world's largest known Holocene lava flows. Katla has been the source of frequent subglacial basaltic explosive eruptions that have been among the largest tephra-producers in Iceland during historical time and has also produced numerous dacitic explosive eruptions during the Holocene.