Spurr

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 61.299°N
  • 152.251°W

  • 3374 m
    11067 ft

  • 313040
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

27 June-3 July 2012

AVO reported that a minor increase in seismicity at Spurr was detected at about 0500 on 25 June, lasted about 45 minutes, and was characterized by several discrete M1earthquakes. The signals recorded were consistent with seismic energy generated by an energetic flow of water, possibly indicating a glacial outburst flood on the lower S flank. The next day seismic levels had declined to near background and no additional flowage signals were observed.

Source: US Geological Survey Alaska Volcano Observatory (AVO)



 Available Weekly Reports


2012: June
2006: January
2005: January | March | April | May | August | September
2004: July | August | September | October | November | December


27 June-3 July 2012

AVO reported that a minor increase in seismicity at Spurr was detected at about 0500 on 25 June, lasted about 45 minutes, and was characterized by several discrete M1earthquakes. The signals recorded were consistent with seismic energy generated by an energetic flow of water, possibly indicating a glacial outburst flood on the lower S flank. The next day seismic levels had declined to near background and no additional flowage signals were observed.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


4 January-10 January 2006

Seismicity remained above background levels at Spurr during 30 December to 6 January. Clear satellite and web camera views of the volcano showed no unusual activity. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


21 September-27 September 2005

Seismicity at Spurr during 16-23 September remained above background levels, but the overall rate continued to gradually decline. Preliminary data from a gas-sensing flight earlier in the week showed a substantial reduction in gas emissions compared to previous measurements taken in May 2005. The declining seismicity, reduced gas emission, and the changing summit-lake color (thought to reflect lower levels of acidity), all suggested a reduced level of volcanic activity. Minor steaming continued from the summit "melt pit" and occasionally from Crater Peak. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


14 September-20 September 2005

During 9-16 September, seismicity at Spurr remained above background levels, but there were several indications that the level of unrest was declining. AVO reported that recent observations of the summit lake showed a change in the water color from slate gray to blue-green, which could be indicative of decreasing sulfur-dioxide gas emissions. In addition, there were no observations of the vigorous upwelling of gases that had been seen in the lake earlier this summer. The overall rate of seismicity gradually declined during the previous several months, further suggesting a reduced level of activity. Minor steaming continued from the summit "melt pit" and occasionally from Crater Peak. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


10 August-16 August 2005

The level of seismic activity at Mt. Spurr decreased during the previous month, but remained above background levels during 5-12 August. Gas and heat emissions remained at elevated levels, and minor steaming continued from the summit "melt/collapse pit." Satellite imagery showed no indications that an eruption was imminent. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


11 May-17 May 2005

Elevated levels of seismicity continue to be recorded during 6-13 May. The AVO webcam images showed small steam plumes during the early part of this week. A pilot report received on 9 May described a small steam plume reaching 60-100 m (200-300 feet) above the summit crater. The crater lake level continues to drop, exposing more areas of steaming rock in the crater walls. Continued heat flux is indicated by vigorously upwelling water in the melt pit lake, rapid melting of ice and snow that has fallen into the lake, and minor steaming from rock surfaces and smaller melt pits in the vicinity of the summit crater. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


4 May-10 May 2005

An approximately 500-m-long debris flow emanating from the ice and snow ESE of the summit melt pit was seen from Anchorage and confirmed by an overflight on 2 May. This debris flow is similar in size and location to those observed in July 2004, just prior to first recognition of the summit melt pit. Clear views of the melt pit showed increased steam emanating from recently exposed rock around the lake, which coalesced to form a weak steam plume that rose above the rim of the melt pit. The lake level had decreased since 25 April, indicating outflow of water from the lake which may have coincided with emplacement of the recent debris flow. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


27 April-3 May 2005

During 22-29 April, elevated levels of seismicity continued to be recorded at Spurr. Thermal imagery taken on 25 April revealed that temperatures in the summit melt-pit region were similar to those recorded in September 2004, with values as high as 40 degrees Celsius in scattered patches of exposed rock. The lake in the summit crater continued to be discolored, and there was a strong scent of sulfur in the area, indicating continued gas emission. The summit melt pit was estimated to be approximately 250 m in diameter, and it continued to widen as the summit snow pack collapsed into the lake. No unusual activity was observed in satellite or web camera images during the report week. Mt. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


2 March-8 March 2005

Elevated levels of seismicity continued to be recorded at Mt. Spurr during 25 February to 4 March. No activity was observed in satellite and web-camera images. AVO staff observed that the "ice cauldron" at the volcano (a collapse feature in the ice possibly caused by increased volcanic heat) had continued to grow since its first sighting in August 2004. Continued heat flux was indicated by vigorously upwelling water in the "melt pit lake" (the nearly ice free lake at the bottom of the "ice cauldron"), rapid melting of ice and snow that had fallen into the melt pit lake, and minor steaming from rock surfaces and small melt pits in the vicinity of the summit dome and Crater Peak cone, 3 km S of Spurr's summit. According to AVO, both Spurr and Crater Peak were emitting volcanic gases, including carbon dioxide, sulfur dioxide, and hydrogen sulfide, which may be hazardous to recreational visitors. Mt. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


12 January-18 January 2005

Elevated levels of seismicity continued to be recorded at Spurr during 8-14 January. Seismic event rates averaged six located earthquakes per day. No activity was observed in satellite and web camera images during 8-14 January.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


5 January-11 January 2005

Seismic unrest continued at Spurr during 1-7 January, with an average of 7 earthquakes recorded per day. No activity was observed in satellite or web camera images during 1-7 January. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


29 December-4 January 2005

Seismic unrest continued at Spurr during 26-31 December, with an average of 5-6 earthquakes recorded per day. A distinct increase in seismicity occurred on 26 December when 25 earthquakes were recorded. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


17 November-23 November 2004

Elevated levels of seismicity continued to be recorded at Mount Spurr. Seismicity rates have been relatively constant in the last week at roughly 5 locatable earthquakes per day. No unusual activity was observed in satellite or web camera images. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


10 November-16 November 2004

Elevated levels of seismicity continued to be recorded at Spurr during 5-12 November. A period of slightly increased seismicity occurred between 6-8 November when as many as three shallow earthquakes per hour were recorded. Since then, the level of seismicity had declined to an average of six earthquakes per day. No unusual activity was observed in satellite or web camera images. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


3 November-9 November 2004

Elevated levels of seismicity continued to be recorded at Spurr during 29 October to 2 November. An earthquake swarm on 4 November consisted of as many as 10 shallow earthquakes per hour during a 6- to 7-hour period. After that, the level of seismicity declined to an average of 0-2 earthquakes per hour. Airborne measurements of volcanic gas from the volcano on 29 and 30 October indicated no significant change in the amount of carbon dioxide or sulfur-bearing gases compared to previous measurements in September. No unusual activity was observed on satellite or web-camera images. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


13 October-19 October 2004

Elevated levels of seismicity continued to be recorded at Spurr during 8-15 October. About 60 earthquakes were recorded within 30 km of the summit, with an average of about nine earthquakes per day. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


22 September-28 September 2004

Elevated seismicity continued at Spurr during 17-24 September, with an average of ten earthquakes occurring within 30 km of the summit daily. The combined output of carbon dioxide from one vent at Crater Peak and one at Spurr was approximately 2,300 tons on 15 September, an increase from the approximately 760 tons/day measured during 7-8 August. AVO reported that the gray color of the lake at the bottom of the ice cauldron is typical of crater lakes containing dissolved sulfur dioxide. These observations further suggest that magma resides beneath the volcano. However, there were no indications that an eruption is imminent, and this type of activity does not always lead to an eruption. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


15 September-21 September 2004

Elevated levels of seismicity continue to be recorded, but have not changed significantly from that observed in the past few weeks. During the week ending on 17 September there were about 85 earthquakes located within 30 km of the summit with an average of approximately 12 per day. Observations of the summit during AVO overflights showed no major changes. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


8 September-14 September 2004

During 3-10 September, elevated levels of seismicity continued to be recorded at Spurr as has been the case for several weeks. About 90 earthquakes were recorded during the report period within 30 km of the summit, with about 13 occurring per day. Observations and photography during the week revealed that the ice pit located near the summit had enlarged substantially (currently about 150 m x 170 m), presumably as the roof of the meltwater basin continued to subside and collapse. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


1 September-7 September 2004

Elevated levels of seismicity continued at Spurr during 27 August to 3 September and did not change significantly in comparison to the previous few weeks. During the report week, 101 earthquakes were recorded within 30 km of the summit, averaging ~14 per day. Although seismicity was greater than typical background levels, there were no signs that an eruption was imminent. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


18 August-24 August 2004

Elevated levels of seismicity continued to be recorded at Spurr during 13-20 August. Seismicity reached a maximum of 70 earthquakes on 14 August, then declined to about 15 earthquakes per day the rest of the week. This was slightly higher than the level recorded during the previous weeks. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


11 August-17 August 2004

Elevated levels of seismicity continued at Spurr during 6-17 August, as it has for several weeks. On 12 August a pilot reported ash in the Hayes River valley N of Spurr. However, AVO found no evidence of an eruption in seismic or satellite data, subsequent pilot reports, or from visual observations. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


4 August-10 August 2004

Elevated levels of seismicity continued at Spurr during 30 July to 6 August, with about 10-20 earthquakes occurring daily beneath the summit. This level of activity had remained relatively constant for the last several weeks. AVO noted that although this represents a notable increase above background seismicity, there were no indications that an eruption was imminent.

Aerial observations of Spurr made by AVO staff during the report week indicated the presence of a circular collapse pit in the snow/ice cover, approximately 50 x 75 meters in diameter on the NE flank of the summit dome at an elevation of approximately 3,110 m a.s.l. The collapse pit appeared to contain standing water of indeterminable depth. Arc-shaped scarps and small translational slumps in the snow/ice cover around the summit dome also were observed. AVO noted that these features and the collapse pit may indicate an increase in heat flux through the summit dome that could be related to the intrusion of magma at depth. Photographs of Spurr's summit taken on 20 June 2004 did not show a collapse pit, but did indicate an arc-shaped scarp in the area where the present collapse pit has formed. Spurr remained at Concern Color Code Yellow.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


28 July-3 August 2004

According to AVO during 22-30 July elevated levels of seismicity continued to be recorded at Spurr, with approximately 10-20 earthquakes occurring daily beneath the summit. The level of activity had remained constant for the previous several weeks. Although this represented a notable increase over background seismicity levels, there was no indication that an eruption was imminent. AVO noted that this type of seismicity often will decline without producing an eruption. Spurr remained at Concern Color Code Yellow.

Sources: US Geological Survey Alaska Volcano Observatory (AVO), Reuters, Associated Press


21 July-27 July 2004

AVO raised the Concern Color Code at Spurr from Green to Yellow on 26 July after an increase in seismicity was recorded beneath the volcano's summit. Some earthquakes were interpreted to reflect the beginning stages of volcanic unrest. AVO noted that there were no indications that an eruption was imminent and that this type of seismicity can decline without leading to an eruption.

Retrospective analysis suggested that the seismic increase began slowly, perhaps as early as February 2004. As of 26 July, the seismic network recorded 15-20 earthquakes daily. This rate was greater than any observed since the last eruptive period in 1992. All earthquakes were less than magnitude 1.5 and ranged in depth between 1 and 6 km below sea level. Relatively few earthquakes were located beneath the Crater Peak vent, the site of the 1953 and 1992 eruptions. On 11 July a pilot reported a strong sulfur smell from Spurr and a new area of steaming, but AVO scientists observed neither during an overflight on 15 July.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1992 Jun 27 1992 Sep 17 Confirmed 4 Historical Observations South flank (Crater Peak)
[ 1954 ] [ Unknown ] Discredited    
1953 Jul 9 1953 Jul 16 Confirmed 4 Historical Observations South flank (Crater Peak)
1650 ± 50 years Unknown Confirmed   Tephrochronology South flank (Crater Peak)
3250 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected) Mt. Spurr central lava/cone complex
4050 BCE (?) Unknown Confirmed   Tephrochronology South flank (Crater Peak)
5110 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected) Mt. Spurr central dome/cone complex
6050 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected) Mt. Spurr central dome/cone complex

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.

Gardner C A, Cashman K V, Neal C A, 1998. Tephra-fall deposits from the 1992 eruption of Crater Peak, Alaska: implications of clast textures for eruptive processes. Bull Volc, 59: 537-555.

Henning R A, Rosenthal C H, Olds B, Reading E (eds), 1976. Alaska's volcanoes, northern link in the ring of fire. Alaska Geog, 4: 1-88.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

McNutt S R, Davis C M, 2000. Lightning associated with the 1992 eruptions of Crater Peak, Mount Spurr volcano, Alaska. J Volc Geotherm Res, 102: 45-65.

Miller T P, McGimsey R G, Richter D H, Riehle J R, Nye C J, Yount M E, Dumoulin J A, 1998. Catalogue of the historically active volcanoes of Alaska. U S Geol Surv Open-File Rpt, 98-582: 1-104.

Motyka R J, Liss S A, Nye C J, Moorman M A, 1993. Geothermal resources of the Aleutian arc. Alaska Div Geol Geophys Surv, Prof Rpt, no 114, 17 p and 4 map sheets.

Nye C J, Turner D L, 1990. Petrology, geochemistry, and age of the Spurr volcanic complex, eastern Aleutian arc. Bull Volc, 52: 205-226.

Power J A, Jolly A D, Nye C J, Harbin M L, 2002. A conceptual model of the Mount Spurr magmatic system from seismic and geochemical observations of the 1992 Crater Peak eruption sequence. Bull Volc, 64: 206-218.

Riehle J R, 1985. A reconnaissance of the major Holocene tephra deposits in the Upper Cook Inlet Region, Alaska. J Volc Geotherm Res, 26: 37-74.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

The 3374-m-high summit of Mount Spurr, the highest volcano of the Aleutain arc, is a large lava dome constructed at the center of a roughly 5-km-wide horseshoe-shaped caldera that is open to the south. The volcano lies 130 km west of Anchorage and NE of Chakachamna Lake. The caldera was formed by a late-Pleistocene or early Holocene debris avalanche and associated pyroclastic flows that destroyed an ancestral Spurr volcano. The debris avalanche traveled more than 25 km to the SE, and the resulting deposit contains blocks as large as 100 m in diameter. Several ice-carved post-caldera cones or lava domes lie in the center of the caldera. The youngest vent, 2309-m-high Crater Peak, formed at the breached southern end of the caldera and has been the source of about 40 identified Holocene tephra layers. Spurr's two historical eruptions, from Crater Peak in 1953 and 1992, deposited ash on the city of Anchorage.