![Seismic recording at Mt Spurr volcano (CKT station, AVO)]()
Seismic recording at Mt Spurr volcano (CKT station, AVO)
![Seismic recording CKT station on 15 Jan (AVO)]()
Seismic recording CKT station on 15 Jan (AVO)
A series of pulsating signals occurred on seismograms at Mount Spurr volcano (AK) earlier on 15 Jan, earthquake-report.com mentions.
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.
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.
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.
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 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.
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.
Wed, 4 May 2005, 06:00
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.
Read allWed, 27 Apr 2005, 06:00
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.
Read allWed, 2 Mar 2005, 06:00
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.
Read allWed, 12 Jan 2005, 06:00
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.
Read allWed, 5 Jan 2005, 06:00
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.
Read allWed, 29 Dec 2004, 06:00
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.
Read allWed, 17 Nov 2004, 06:00
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.
Read allWed, 10 Nov 2004, 06:00
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.
Read allWed, 3 Nov 2004, 06:00
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.
Read allWed, 13 Oct 2004, 06:00
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.
Read allWed, 22 Sep 2004, 06:00
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.
Read allWed, 15 Sep 2004, 06:00
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.
Read allWed, 8 Sep 2004, 06:00
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.
Read allWed, 1 Sep 2004, 06:00
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.
Read allWed, 18 Aug 2004, 06:00
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.
Read allWed, 11 Aug 2004, 06:00
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.
Read allWed, 4 Aug 2004, 06:00
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.
Read allWed, 28 Jul 2004, 06:00
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.
Read allWed, 21 Jul 2004, 06:00
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.
Read all
