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June 1, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. During such eruptions, changes in the level of activity can occur over days to months. The eruption could intensify suddenly or with little warning and produce explosions that cause hazardous conditions within several miles of the crater and farther downwind. Small lahars could suddenly descend the Toutle River if triggered by heavy rain or by interaction of hot rocks with snow and ice. These lahars pose a negligible hazard below the Sediment Retention Structure (SRS) but could pose a hazard along the river channel upstream.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward.
- Potential ash hazards to aviation: Under current eruptive conditions, small, short-lived explosions may produce ash clouds that exceed 30,000 feet in altitude. Ash from such events can travel 100 miles or more downwind.
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- Recent observations: Seismicity and repeat photos from remote cameras confirm that extrusion of the lava spine formerly known as “the fin” is continuing. A large rockfall and avalanche from the spine on May 29 damaged tiltmeter, seismometer, and GPS stations on the northeast flank of the 1980-1986 lava dome. They will be repaired or replaced as soon as weather permits, but probably not before early next week. Additional rockfalls from the growing spine are likely in the coming days. Such events could generate dust plumes that rise above the crater rim. Any resulting deposit would likely be very thin and confined mostly to the crater and outer flanks of the volcano.
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June 2, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward.
- Recent observations: Clouds are obscuring the view into the crater from Johnston Ridge Observatory this morning, and the weather will preclude any field work until next week at the earliest. Seismicity remains at a level typical of recent days and weeks, indicating that lava extrusion is continuing. As soon as weather allows, priority for field operations will be given to replacing or repairing the monitoring instruments on the 1980-1986 dome that were damaged by the rockfall and avalanche of May 29.
June 3, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward.
- Recent observations: There have been glimpses through patchy clouds into the crater from Johnston Ridge Observatory this morning. Persistent seismicity and pictures from a remote camera on the northeast crater rim (Brutus) show that lava extrusion is continuing. The spine that has been growing since October-November 2005 continues to emerge through talus from recent rockfalls, and additional rockfalls are occurring as a result. None has approached the size of the event on May 29, but comparably-sized events are possible as the spine continues to grow. As noted earlier, hazards from such an event are not expected to extend beyond the crater. A small amount of rockfall dust could rise above the crater rim and drift downwind, as was the case on May 29.
June 4, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward early in the day, shifting to eastward this afternoon and evening.
- Recent observations: Clouds have so far obscured the view into the crater this morning from Johnston Ridge Observatory, but conditions are forecast to improve later in the day. Seismicity continues at a level typical of recent days, indicating that lava extrusion is continuing. Photos acquired from a remote camera at Brutus on the northeast crater rim as recently as yesterday show the base of the active spine continuing to emerge from talus, accompanied by occasional small rockfalls. Crews hope to take advantage of the improving weather pattern make observations and repair monitoring equipment in the crater starting on Monday.
June 5, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward.
- Recent observations: The weather is improving and field crews are hoping to visit the crater today for the first time since May 30 to make repairs and observations. Seismicity and photos from the Brutus camera on the northeast crater rim indicate that lava extrusion and rockfalls from the growing spine are continuing. Some of the larger rockfalls can be expected to cause dust plumes that could rise above the crater rim and be visible from Johnston Ridge Observatory and elsewhere in the vicinity.
June 6, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward.
- Recent observations: The crater is partly obscured by low clouds this morning. Field parties yesterday repaired a seismic station, serviced several GPS stations, repaired a camera, and examined deposits from last week’s Memorial Day avalanche. Seismicity and repeat photography indicate that lava extrusion and rockfalls from the growing spine are continuing. Some of the larger rockfalls can be expected to cause dust plumes that could rise above the crater rim and be visible from Johnston Ridge Observatory and elsewhere in the vicinity.
June 7, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that any ash clouds that rise above the crater rim today would drift northeastward.
- Recent observations: Low-level clouds continue to shroud the mountain this morning and prevent visual observations. Our instrumentation, however, indicates that there has been no change in the level or character of seismicity in the past 24 hours. Overall, the seismicity indicates that lava extrusion and rockfalls from the growing spine are continuing. Some of the larger rockfalls might loft dust plumes that rise above the crater rim, which, if clouds clear, could be visible.
June 8, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that low-level (up to 7 km) ash clouds rising above the crater rim this morning and early this afternoon would drift ESE; higher ash clouds would move NE. Late this afternoon and this evening, winds at all levels would transport ash SE.
- Recent observations: Views into the crater are blocked by clouds this morning. Our instruments indicate that there has been no change in the level or character of seismicity in the past 24 hours. Small earthquakes are occurring at the rate of one every 1 to 3 minutes, indicating that lava extrusion is continuing. Rockfalls from the growing spine are occurring sporadically; one at 9:06 pm last evening raised a dust cloud about 2000 feet above the crater rim. We expect rockfall activity to continue. Larger rockfalls will loft dust plumes that should be visible above the crater rim if the weather is clear.
June 9, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater would be transported to the southeast throughout the day today.
- Recent observations: Views into the crater are blocked by clouds this morning but may be open in the afternoon. The level and character of seismicity has not changed in the past 24 hours. Small earthquakes are still occurring at the rate of one every 1 to 3 minutes, indicating that lava extrusion is continuing. Rockfalls from the growing spine may be expected to occur sporadically in the foreseeable future. Some larger rockfalls will loft dust plumes a few thousand feet above the crater rim that should be visible if the weather is clear.
June 10, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater would be transported to the southwest early today and to the south or east later today.
- Recent observations: Clouds obscure views into the crater today. An earthquake (M3.2) and rock-fall avalanche occurred last night at 9:04 p.m. PDT (0404 UTC). Pilots reported a steam plume that rose above the crater rim associated to this event. The plume contained very little ash and communities downwind reported no ash fall, but a thin coat of ash to the west of the spine appears in crater photos. Small earthquakes are occurring at the rate of one every 1 to 3 minutes, indicating continuing lava extrusion. Rockfalls from the growing spine are likely to occur sporadically in the foreseeable future. Some larger rockfalls, such as that of last night, will loft ash plumes a few thousand feet above the crater rim.
June 11, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater would be transported to the southwest all levels until late this afternoon. This evening lower level winds will continue to move ash to the southwest, but upper level winds (for ash column to 12 km) would blow to the northeast.
- Recent observations: The crater is free of clouds this morning. The level and character of seismicity has not changed in the past 24 hours. Small earthquakes are still occurring at the rate of one every 1 to 3 minutes, indicating that lava extrusion is continuing. Rockfalls from the growing spine may be expected to occur sporadically in the foreseeable future. Ventings of steam associated with larger rockfalls this past week have lofted ash to about 15,000 feet.
June 12, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported northeastward.
- Recent observations: High clouds this morning permit observation of the volcano, which shows steaming from the lava dome. Breaks in clouds permitted observation of two small rock-fall events between 12 a.m. and 1 a.m. PDT last night. Small earthquakes, occurring at the rate of one every 1 to 3 minutes, and repeat photographs from the crater rim in the past several days indicate continuing lava extrusion. Rockfalls from the growing spine are likely to occur sporadically in the foreseeable future. Some larger rockfalls will loft ash plumes a few thousand feet above the crater rim.
June 13, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported northeastward.
- Recent observations: Low clouds this morning obscured observation of the volcano, though photos from the east rim show steaming from the lava dome. Small earthquakes, occurring at the rate of one every 1 to 3 minutes, and the repeat photographs from the crater rim in the past several days indicate continuing lava extrusion. Rockfalls from the growing spine are likely to occur sporadically in the foreseeable future. Some larger rockfalls will loft ash plumes a few thousand feet above the crater rim.
June 14, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported toward the east or northeast.
- Recent observations: A medium-sized rockfall event yesterday evening at ~6:00PM PDT was recorded on our seismic stations. This is the most recent of several rockfalls since Memorial Day that have been breaking apart the spine that grew between March and May of this year. The lobe on which the decrepitating spine stands continues to rise, accompanied by small “drumbeat” earthquakes that recur at the rate of one every few minutes.
June 15, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported toward the east or northeast.
- Recent observations: Over the past day, a few small rockfall events followed the large event on June 13, 2006, as indicated by small signals on crater seismic stations. Thus the processes breaking apart the spine that grew between March and May of this year continues. The lobe on which the decrepitating spine stands continues to rise, accompanied by small “drumbeat” earthquakes that recur at the rate of one every few minutes.
June 16, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported toward the east or northeast.
- Recent observations: Yesterday evening the clouds parted long enough that three of our remote cameras could view the growing dome. The photos illustrate that the remnant of the collapsed spine remains the high point on the active, west lobe of the lava dome. The rate of small rockfall events has diminished in the past few days, though the lobe on which the decrepitating spine stands continues to rise, accompanied by small “drumbeat” earthquakes that recur at the rate of one every few minutes.
June 17, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported to the east.
- Recent observations: The rate of small rockfall events continues to diminish, accompanied by a decreasing number of small earthquakes. Though visibility continues to be limited, the continued seismicity and ground deformation indicates that the dome is still growing.
June 18, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported toward the east.
- Recent observations: This morning the lava dome is shrouded in clouds. Small “drumbeat” earthquakes have increased slightly in amplitude in recent days though not to a degree that would signal dramatic new behavior. No other significant new activity.
June 19, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would be transported toward the east.
- Recent observations: A number of small earthquakes in the last 24 hours have triggered rockfalls that lasted 1-2 minutes, and some have been followed tens of minutes later by continued rockfall activity as the growing dome continues to fall apart and spread. The dust clouds produced by the rockfalls have not made it over the crater rim. No other significant new activity has occurred.
June 20, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift to the east-southeast today.
- Recent observations: Several minor rockfalls occurred overnight, alongside the regular “drumbeat” earthquakes. Occasional rockfalls, some of appreciable size that may produce dust clouds reaching over the crater rim, are to be expected as the new dome continues to grow and fall apart. Weather permitting, field crews hope to put in a full day of work around the volcano today. Items on the to-do list include retrieving a number of damaged seismic and GPS instruments in the crater (including several “spiders”), installing several replacement seismic “spiders”, deploying a number of temporary GPS instruments on the flanks, perform water sampling surveys, and other work as time allows.
June 21, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift to the east-southeast today.
- Recent observations: The first day of summer begins much as the last day of spring ended, with many small earthquakes occurring along with occasional rockfalls. Visual surveys made yesterday provide independent confirmation that dome extrusion continues unabated. Field crews had a successful day in the crater yesterday. A number of instruments (“spiders”) damaged by snow and/or rockfalls were retrieved, two seismic “spiders” were repaired and redeployed at their original locations, and new GPS “spiders” were installed on the western arm of the main glacier and on an older part of the growing lava dome. Field crews also serviced several additional seismic sites and repaired the Sugarbowl camera. Finally, hydrologic surveys were performed on two streams that have outlets in the crater. Field plans for today include servicing several more cameras located on the crater rim, deploying several temporary GPS stations, and performing additional hydrologic surveys.
June 22, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift to the east today.
- Recent observations: Images from remote cameras and data from GPS instruments installed on the west glacier and new lava dome complex indicate that lava extrusion continues unabated, with no significant changes in seismicity over the last 24 hours. Field crews had another successful day at the volcano yesterday. A time-lapse camera was temporarily deployed on the new dome complex in an attempt to record small-scale motions of the growing spine. In addition, several temporary GPS stations were retrieved and deployed at additional locations around the volcano, and several hydrologic surveys were performed. More fieldwork is planned for today, with field crews doing additional GPS deployments, servicing several cameras on the crater rim, and performing geological reconnaissance on an older part of the new lava dome complex.
June 23, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift to the east-southeast today.
- Recent observations: Seismicity accompanying steady lava dome extrusion continues unabated, with small earthquakes occurring every 1-2 minutes. With clear and warm weather forecast through early next week it is possible that ash clouds from large rockfalls will on occasion be visible from the Portland area, and views of the crater and ongoing eruption should be excellent from the US Forest Service’s visitor’s centers at Coldwater Ridge and Johnston Ridge. Field crews yesterday completed a campaign GPS survey of benchmarks in the National Volcano Monument, spent several hours doing geological reconnaissance on the eastern (older) side of the new dome complex, and serviced several remote cameras on the crater rim. More fieldwork is planned for today, with field crews retrieving a number of temporary seismometers deployed last fall and exploring potential locations for a new remote camera station on the crater rim.
June 24, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift to the east today.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. Field crews yesterday retrieved a number of temporary seismometers deployed in the summer of 2005 and explored potential locations for a new remote camera station on the crater rim. Today’s clear, warm weather and resultant good visibility make it possible that ash clouds from large rockfalls will on occasion be visible from the Portland area, and views of the crater and ongoing eruption should be excellent from the US Forest Service’s visitor’s centers at Coldwater Ridge and Johnston Ridge.
June 25, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift slowly to the west-southwest.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. Views from the US Forest Service’s web camera at the Johnston Ridge Observatory are clear this morning and show a small steam plume emanating from the new lava dome, as well as a dust cloud from the Loowit Falls area north of the crater (on the left-hand side of the JRO image). Continued clear and hot weather today will make for excellent views of the ongoing eruption from the US Forest Service’s visitor’s centers at Coldwater Ridge and Johnston Ridge. It is also possible that ash clouds from large rockfalls will on occasion be visible from the Portland area.
June 26, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds that rise above the crater rim would drift slowly to the west today.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. A large rockfall occurred yesterday evening at 4:59pm, producing a small ash cloud that could be seen from the Portland area.Views from the US Forest Service’s web camera at the Johnston Ridge Observatory are clear this morning and show a small steam plume emanating from the new lava dome, as well as dust coming from minor rockfalls on the crater walls and the growing lava dome. Continued clear and hot weather today will make for excellent views of the ongoing eruption from the US Forest Service’s visitor’s centers at Coldwater Ridge and Johnston Ridge. Occasional sizeable rockfalls may produce ash clouds large enough to be visible from the Portland area.
June 27, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would drift slowly toward the east.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. The largest rockfalls produce small ash clouds that occasionally escape from the crater. Time-lapse photographs of the east face of the lava dome show that it is extruding at a rate of about 1.5 meters per day, consistent with other recent estimates. Emission of volcanic gas remains at a very low level. A GPS station on the old dome that lost power over the weekend will be replaced later this week. No other significant new activity has occurred.
June 28, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would drift northeastwardly.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. With clear weather forecasted it is possible that ash clouds from large rockfalls will on occasion be visible. Today, field crews are installing a new tiltmeter on the north side of the 1980-86 lava dome and continue to harden the GPS network around the volcano. Tomorrow, crews will finish installing the tiltmeter, do a thermal imagery flight and look for a new camera site on the southeast rim of the volcano.
June 29, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would drift northeastwardly.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. With clear weather forecasted it is possible that ash clouds from large rockfalls will on occasion be visible. Today, field crews are acquiring thermal and photographic images of the new lava dome, surveying stream channels around Loowit Falls, and retrieving surveying gear from several campaign GPS stations. Yesterday, a new tiltmeter station was installed on the north side of the old lava dome and a new continuous GPS station was installed north of Mount St. Helens.
June 30, 2006:
- Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE:
- Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.
- Wind forecasts show that ash clouds rising above the crater today would drift northeastwardly.
- Recent observations: Small earthquakes accompanying lava dome extrusion continue to occur every 1-2 minutes, punctuated by occasional rockfall signals on seismic records. A sequence of images from the south rim camera record continued upward extrusion of a lava spine. This growth is displacing unstable spine remnants and surrounding talus, which frequently cascade down in rockfalls. With clear weather forecasted it is possible that ash clouds from large rockfalls will on occasion be visible. Yesterday's thermal scans from a helicopter found the highest temperature (600 degrees C) on the backside of the highest point of the spine and a ring of 200 to 300 degrees C rock at the base of the spine. Data from campaign GPS receivers retrieved yesterday is being analyzed to determine the long-term pattern of regional ground deformation.
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