(Top row) Observed and (bottom row) best-fit synthetic ERS interferograms of Mount Veniaminof. AVO received video footage recorded in early October that showed minor ash emission from the intracaldera cone. Over the week of 5-10 March, seismicity was low but slightly above background. Although clear weather prevailed . The E part of this feature closely approached, but did not touch, the depression in the ice observed 2 days earlier. During 4-6 September pulsating, low-altitude ash plumes were visible from a Perryville webcam and reported by a pilot, and a small thermal anomaly was visible in satellite data. As noted above and in table 1, non-eruptive steaming prevailed at the volcano during much or all of the interval 4 May 2008-7 May 2009. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email. In modern times the volcano has had numerous small eruptions (over ten of them since 1930), all at a cinder cone in the middle of the caldera. Observers in Port Heiden . The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange. A white steam cloud was present during the intervals between black emissions. Prior to an eruptive episode that began in June 2013, lava had last erupted during Strombolian activity in February 2005; subsequent minor ash emissions occurred later in 2005, November 2006, and February 2008. The Aviation Color Code remained at Orange (the second highest level on a four-color scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale). and drifted W. Seismic tremor has remained high on 13 August. Volcanic tremor at Veniaminof increased during 30 September-1 October, prompting AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. On 21 November observations and FAA webcam images indicated continuous ash emissions through most of the day as ash plumes drifted SE, extending as far as 400 km (figure 31). Early 25 June, ash was moving NE at 3.5-4 km altitude and several ash puffs were observed that afternoon. Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of a) U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667 USA (URL: https://avo.alaska.edu/), b) Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and c) Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://dggs.alaska.gov/); Anchorage Volcanic Ash Advisory Center (VAAC), Alaska Aviation Weather Unit, NWS NOAA US Dept of Commerce, 6930 Sand Lake Road, Anchorage, AK 99502-1845 USA (URL: http://vaac.arh.noaa.gov/); Hawai'i Institute of Geophysics and Planetology (HIGP) - MODVOLC Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. Lava flowed into the W part of the dumbbell and sank into the ice, from which billowing clouds of steam were rising. On 16 July 2013 an AVO geologist visited the caldera by helicopter, making observations and taking the first close-up photographs documenting the lava flows and ice cauldron formation (figure 19). Elevated surface temperatures were identified in satellite images, and seismicity remained elevated. Eruptive activity continued through early March. . The increase continued through 11 February. A "warm" spot, detected on AVHRR satellite images, persisted from 17 June through 1 July. Satellite images detected a thermal signal at the intracaldera cone. Incandescent lava flow; low-level steam-and-ash plumes. The Alaska Volcano Observatory (AVO) received reports ranging from minor-steam and possible ash emissions, to no signs of activity. Information Contacts: M.E. Variable seismicity contined to be recorded from October 2002 through mid-April 2003 accompanied by steam emissions from the intracaldera cone (BGVN 28:01 and 28:03). Cloudy conditions throughout October and the first half of November prevented observations on most days. Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/); Charles R. Holliday, Air Force Weather Agency (AFWA), Offutt Air Force Base, NE 68113. Whether each one represented an active lava flow or some combination of cooling lava, water, and ice field was unknown. These clouds typically were confined to the summit caldera, but could pose a hazard to people and low-flying aircraft in the immediate vicinity of the active cone. . Satellite imagery on 26 May showed ash deposits on the N and SE portions of the caldera. . Gas and steam was seen rising sparsely and discontinuously over the surface of the lava field. On 7 and 8 July, lava fountaining was continuing and bombs rose to about 100 m above the cone. Residents of Perryville reported a "black puff" of ash on 16 February followed by strong steaming, and a pilot reported a small black ash cloud on 19 February. None appeared to have exceeded 3,000 m altitude. . The elevated seismicity that began at Veniaminof in mid-December 2002 continued through 24-31 January. On 30 April AVO lowered the Aviation Color Code for Veniaminof to Green and the Volcano Alert Level to Normal, noting that signs of unrest had continued to decline over the previous four months since the eruption ended in early January. AVO has no seismic monitoring equipment on Veniaminof and for this reason is not using the Level of Concern Color Code. The summit of the main intracaldera cone was generally shrouded in steam and clouds (at about 2,400 m above sea level) but was obviously degassing vigorously, similar to 1983-84. Coats R R, 1950. AVO lowered the Volcano Alert Level to Normal for Veniaminof and the Aviation Color Code to Green on 25 August, noting that the volcano returned to background activity after low-level tremor was detected and a pilot saw steaming on 1 August. On 14 January, a satellite image showed a thermal anomaly in the vicinity of the Veniaminof summit. It is a stratovolcano that comprises the entire western half of Chuginadak Island. Volcanoes of North America. Erupted at least 36 times in the last 30 years. Residents of Perryville (~ 30 km S) reported a "black puff" of ash on 16 February, followed by strong steam emissions. See their reports for more details. Sequences of tremor accompanying ash bursts continued. The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange. The tremor occurred in pulses lasting several minutes. Broadly during late February 2008, AVO noted both small ash bursts with local ashfall at the crater accompanied by seismicity, and occasional high thermal fluxes. No eruptive activity was evident in satellite and webcam images on the morning of 13 December. AVO reported that the eruption of Veniaminof continued during 18-25 June, indicated by volcanic tremor detected by the seismic network. Unrest during the week of 16 May was characterized by moderate levels of intermittent volcanic tremor, which was similar to the seismic signals recorded in association with the small ash emissions of 25 and 28 April and 1-3 May. During 21-28 May, the level of volcanic activity at Veniaminof was generally lower than during the previous week. Fractures in the ice sheet adjacent to the lava flow field continued to grow due to meltwater flowing beneath. The Anchorage Volcanic Ash Advisory Center (VAAC) reported on 15 June 2013 that the eruptions had ended, but AVO still reported intermittent activity continuing through 8 July 2013. Seismicity was similar to levels observed during the previous week, consisting of low-amplitude volcanic tremor with occasional larger bursts. AVO expected that steam-and-ash emissions may continue intermittently for days to weeks and could pose a hazard to people and low-flying aircraft in the vicinity of the active cone. Small amounts of dark ash were seen in the ice-filled caldera on 27 June. Expand each entry for additional details. On 26 March 2006, a pilot reported a small ash plume rising above the volcano. The Aviation Color Code remained at Orange (the second highest level on a four-color scale) and the Volcano Alert Level remained at Watch (the second highest level on a four-level scale). Small ash emissions were observed during clear weather on 25 and 28 April rising to ~1 km above the active cone. At 2323 a pilot observed ash at an altitude of 3.7 km (12,000 ft) a.s.l. Information Contacts: T. Miller and M.E. Eruptive activity continued through mid-March, but declined late March-early April. Low-amplitude continuous tremor was detected. AVO reported that seismic tremor was detected at Veniaminof on 12 June. However, AVO reported that there were no indications from seismic data that a significantly larger eruption was imminent. AVO received no pilot reports of continuing eruptive activity in early June. During 6-7 May, seismic activity from Veniaminof increased, prompting AVO to raise the Volcanic Alert Level to Advisory and the Aviation Color Code to Yellow. AVO reported that the eruption at Veniaminof continued during 19-25 September, as evidenced by nighttime incandescence recorded by the FAA web camera in Perryville (35 km S), elevated surface temperatures in thermal satellite data, and elevated seismic activity. AVO reported that the eruption from the cone in Veniaminof’s ice-filled summit caldera, continued during 31 October-6 November. Volcanic tremor continued to be detected. Clear views earlier on 30 May showed steam emissions from near the base of the intracaldera cone, which rarely rose above the top of the cone. Snow on the upper S flank was gray, indicating a light ash cover. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch. Only minor ash emission was observed, although thin tephra deposits surrounded the volcano, perhaps reaching a thickness of a few centimeters SW of the cone. . Ash deposits extended onto the snowfield at and below the summit to the SSW and SE, forming a "v" shape downslope from the summit. Vigorous steaming had been observed after dark on 11 June but the activity was distinctly stronger on the 15th. Veniaminof (United States) Ash emissions in January and Strombolian eruptions in February. A large vapor cloud was observed on the 23rd and a dark ash cloud was "glimpsed" on the 28th. Veniaminof remained at Concern Color Code Orange. A vigorous fumarolic plume rose from the margin of the lava field E of the active flow. Without additional observations, AVO could not determine if this indicated very low-level eruptive activity or vigorous steaming from the cone. Intermittent, very small-volume steam and ash bursts from the intra-caldera cone have been typical of this volcano intermittently over the past few years, and this pattern continued. Due to the lack of significant seismic activity beneath the volcano, AVO concluded that these small ash clouds were the result of minor explosions caused by the heating of ground water below the intracaldera cone. Except for part of its steep S slope, however, it was snow-covered, indicating a lack of recent activity. A reduction in activity at Veniaminof during 25 February to 4 March led AVO to reduce the Concern Color Code from Yellow to Green, the lowest level. Minor steam-and-ash plumes were sometimes visible during clear daytime conditions. Although seismic activity decreased during 31 July-2 August, it still remained above background levels, and small discrete events continued to be detected. No visual observations of ash emissions had been made since 22 July, although the recorded seismicity was similar to that observed during ash emissions in the previous weeks. Lava flowed SW from the vent on top of flows erupted June-July, adding a new lobe to the lava delta at the base of the intra-caldera cone. AVO determined that the small ash bursts were most likely the result of minor explosions caused by the heating of ground water below the intracaldera cone. On 22 July at 1229, an AVO field crew witnessed a small ash burst rise a few hundred meters above the summit of the intracaldera cone. During 7-14 May unrest continued at Veniaminof, characterized by intermittent low-level volcanic tremor and small volcanic earthquakes. The Anchorage Volcanic Ash Advisory Center (VAAC) reported a steam/ash plume noted on web-cam and satellite on 13 March 2006 at 0500Z (12 March 2006 at 2000 hours local), moving NNW at 9.2 km/hr and falling to the land surface. Figure 15 shows a photo taken on 26 June. The Aniakchak, Cerberus, Gareloi, Great Sitkin, Pavlof, Veniaminof, and Wrangell subnetworks had insufficient numbers of located earthquakes to calculate a Mc. The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange. Veniaminof remained at Concern Color Code Yellow. On 26 September lava fountains, visible in webcam images, rose from a second vent located 75 m N of the vent producing lava flows. During 6-13 August, frequent small ash-and-steam emissions from Veniaminof were visible on the web camera in Perryville and confirmed by AVO geologists working in the area. Seismic activity fluctuated but remained above background levels. Seismicity at Veniaminof and Westdahl were the only areas in which an increase over the seismicity in 2009 was noted. 1). Minor ash-and-steam emissions likely continued, but effusion of lava may have slowed down or possibly stopped. Low-level seismic unrest continues at Veniaminof. The tremor was similar to seismic signals recorded the previous month in association with small ash plumes, suggesting that ash bursts continued. Alaska Geog, 4: 1-88. During the week ending 28 July, an AVO field party flew over the summit and observed typical steaming from the intra-caldera cone with no signs of recent ash emissions. On 22 February several minor ash bursts from Veniaminof were recorded by the seismic network and observed on web camera footage. On 14 October residents of Perryville observed continued emission of a gray steam-and-ash plume to about 1 km above the summit. On 19 August a helicopter overflight revealed two lava flows On 20 August, trace ash fall reported in Perryville ((32 km SSE); they also heard hearing explosions; infrasound equipment in Dillingham (322 km NE) also detected impulses. On 9 February, an ash burst rose hundreds of meters above the intracaldera cone. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch. Unrest continued at Veniaminof during 14-21 May, characterized by intermittent volcanic tremor.