Alaska’s Mount Redoubt erupts again
CNN) -- Mount Redoubt volcano in southern Alaska has erupted again, shooting ash as high as 45,000
feet in the air on Saturday, experts said.
The eruption occurred at about 1:30 p.m. (5:30 p.m. ET), the U.S. Geological Survey told CNN.
Some of the ash fell around Anchorage, resulting in closing of the airport, the Federal Aviation
Administration said.
The volcano erupted three times Friday, at times shooting ash as high as 51,000 feet.
The eruptions are the latest in a series that began March 22.
The Alaska Volcano Observatory has set the alert level at its highest possible designation -- red -indicating that an eruption is under way or imminent and that the eruption will produce a "significant
emission of volcanic ash into the atmosphere."
Friday's volcano activity prompted Alaska Airlines to limit flights to and from Anchorage, according to
the airline's Web site. It canceled all its Thursday flights to and from Anchorage after an eruption earlier
in the day sent an ash cloud 65,000 feet high.
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Volcano
A volcano is a mountain that opens downward to a reservoir of molten rock below the surface of the
earth. Unlike most mountains, which are pushed up from below, volcanoes are built up by an
accumulation of their own eruptive products. When pressure from gases within the molten rock becomes
too great, an eruption occurs. Eruptions can be quiet or explosive. There may be lava flows, flattened
landscapes, poisonous gases, and flying rock and ash.
Because of their intense heat, lava flows are great fire hazards. Lava flows destroy everything in their
path, but most move slowly enough that people can move out of the way.
Fresh volcanic ash, made of pulverized rock, can be abrasive, acidic, gritty, gassy, and odorous. While
not immediately dangerous to most adults, the acidic gas and ash can cause lung damage to small
infants, to older adults, and to those suffering from severe respiratory illnesses. Volcanic ash also can
damage machinery, including engines and electrical equipment. Ash accumulations mixed with water
become heavy and can collapse roofs. Volcanic ash can affect people hundreds of miles away from the
cone of a volcano.
Sideways directed volcanic explosions, known as "lateral blasts," can shoot large pieces of rock at very
high speeds for several miles. These explosions can kill by impact, burial, or heat. They have been
known to knock down entire forests.
Volcanic eruptions can be accompanied by other natural hazards, including earthquakes, mudflows and
flash floods, rock falls and landslides, acid rain, fire, and (under special conditions) tsunamis.
Active volcanoes in the U.S. are found mainly in Hawaii, Alaska, and the Pacific Northwest. Active
volcanoes of the Cascade Mountain Range in California, Oregon, and Washington have created
problems recently. The danger area around a volcano covers approximately a 20-mile radius. Some
danger may exist 100 miles or more from a volcano, leaving Montana and Wyoming at risk.
If a Volcano Erupts Where You Live
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Follow the evacuation order issued by authorities and evacuate immediately from the volcano
area to avoid flying debris, hot gases, lateral blast, and lava flow.
Be aware of mudflows. The danger from a mudflow increases near stream channels and with
prolonged heavy rains. Mudflows can move faster than you can walk or run. Look upstream
before crossing a bridge, and do not cross the bridge if a mudflow is approaching.
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Avoid river valleys and low-lying areas.
Remember to help your neighbors who may require special assistance - infants, elderly people,
and people with disabilities.
Protection from Falling Ash
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Listen to a battery-powered radio or television for the latest emergency information.
If you have a respiratory ailment, avoid contact with any amount of ash.
Wear long-sleeved shirts and long pants.
Use goggles and wear eyeglasses instead of contact lenses.
Use a dust mask or hold a damp cloth over your face to help with breathing.
Stay away from areas downwind from the volcano to avoid volcanic ash.
Stay indoors until the ash has settled unless there is a danger of the roof collapsing.
Close doors, windows, and all ventilation in the house (chimney vents, furnaces, air conditioners,
fans, and other vents.
Clear heavy ash from flat or low-pitched roofs and rain gutters.
Avoid running car or truck engines. Driving can stir up volcanic ash that can clog engines,
damage moving parts, and stall vehicles.
Avoid driving in heavy ash fall unless absolutely required. If you have to drive, keep speed down
to 35 MPH or slower.
Frequently Asked Questions About Volcano Monitoring
To anticipate the awakening or reawakening of a volcano, volcanologists watch for changes caused by
moving or pressurizing magma and associated changes in the hydrothermal system surrounding the
magma. Magma moving toward the surface can cause swarms of earthquakes; swelling, subsidence, or
cracking of the volcano's flanks; and changes in the amount or types of gases that are emitted from a
volcano. The USGS continuously monitors many volcanoes in the states of Washington, Oregon,
California, Hawaii, Alaska, and Wyoming (Yellowstone) to detect unusual activity.
Q: Why is it important to monitor volcanoes?
A: The United States and its territories contain 169 geologically active volcanoes, of which
54 volcanoes are a very high or high threat to public safety. Many of these volcanoes have
erupted in the recent past and will erupt again in the foreseeable future. As populations increase,
areas near volcanoes are being developed and aviation routes are increasing. As a result, more
people and property are at risk from volcanic activity. Future eruptions could affect hundreds of
thousands of people. To help prevent loss of life and property, the U.S. Geological Survey and its
partners monitor these volcanoes, and issue warnings of impending eruptions. Monitoring active
volcanoes allows scientists, public officials, and people in communities at risk to make
preparations that can reduce losses during an eruption.
Q: Why is monitoring volcanoes important to aviation?
Most of the U.S. volcanoes can pose a serious hazard to domestic and/or international
aviation. Below is a summary of KLM Flight 867, a Boeing 747 with more than 240 passengers
aboard, that encountered ash from the 1989 eruption of Mt. Redoubt near Anchorage, Alaska.
The ash encounter provides an example of how volcano monitoring is important to domestic and
international aviation. The following account is summarized by Captain Terry McVenes,
Executive Air Safety Chairman Air Line Pilots Association, International before the Committee
on Commerce, Science, and Transportation Subcommittee on Disaster Prevention and
Prediction. U.S. SENATE March 16, 2006
To classify this encounter as one presenting grave danger for those 240 passengers and that crew
is an understatement! All four engines of this aircraft failed within 59 seconds! A false cargo
compartment fire warning indication required special attention by the crew. All normal airspeed
indications failed! The avionics compartments containing all of the radio, radar, electronic
systems monitoring, and communications systems, all overheated and individual systems failed.
The sophisticated electronic cockpit displays became an electronic nightmare [and the cockpit
filled with smoke]. While ash was contaminating the engines and causing them to flame out, it
was also contaminating electrical compartments and shorting electronic circuit boards. This four
engine jumbo jet was essentially a glider for several minutes until the crew was able to
individually re-start engines. Three of the engines eventually re-started but delivered reduced
performance. The fourth engine eventually came on line when the aircraft was on final approach
to Anchorage. Although the crew landed safely, the encounter caused $80 million dollars
damage to the airplane. Under only slightly different circumstances, 240 plus fatalities and a total
hull loss could have been the result.
KLM 867 was only one of several commercial aircraft exposed to varying amounts of damage
during several days of volcanic activity from Mt. Redoubt. Anchorage is one of the world's
busiest airports for both passengers and cargo. The eventual economic impact of aircraft
damages, cargo delays, passenger flight delays and cancellations, and general disruption to the
Alaskan economy was staggering. Every commercial aviation operation in or through that
territory suffered economic consequences.
The USGS works with the Federal Aviation Association to provide information about
volcanic unrest and potential eruptions. The information is used to reroute flights and reduce the
risk of future ash encounters.
Q: How does the USGS monitor volcanoes in the United States?
A: In cooperation with universities and state agencies, the USGS monitors seismic activity,
ground deformation, volcanic gases, and changes in water levels and chemistry. When unusual
activity is detected, a response team may do more ground surveys and install more instruments,
if possible, to better determine if an eruption is likely.
Q: Does the USGS have a team of volcanologists that can respond to volcanic unrest on short
notice?
A: Yes. The USGS Volcano Hazards Team includes experts in all aspects of volcano hazard
assessment, monitoring, information dissemination, and volcano-emergency response.
Q: Does the USGS have a team for rapid response to volcano emergencies abroad?
A: Yes. Such a team is operated by the U.S. Geological Survey as part of the Volcano Disaster
Assistance Program (VDAP). The team was formed in cooperation with the U.S. Office of
Foreign Disaster Assistance (OFDA) of the U.S. State Department following the 1985 eruption
of Nevado del Ruiz Volcano, Colombia, in which over 23,000 people lost their lives. At the
request of host countries and working through OFDA, VDAP scientists quickly determine the
nature of volcanic unrest and assess its possible consequences. VDAP has responded to volcano
emergencies in more than a dozen countries during the past decade.
In addition to helping people in other countries to get out of harm's way, VDAP's
international work directly benefits volcano-hazard mitigation in the United States. Through
VDAP, we gain experience at active volcanoes that will help during future crises in the western
United States, and we collect important scientific data on eruption precursors that are used to
better understand how U.S. volcanoes work.
Q: How are earthquakes monitored?
A: By installing seismometers that send information continuously via radio to a central recording
site (observatory), scientists can determine the sizes and locations of earthquakes near a volcano.
They look for specific types of earthquakes that are often associated with volcanic activity,
including long- period volcanic earthquakes and volcanic tremor.
Q: How are ground movements measured?
A: Ground deformation (swelling, subsidence, or cracking) is measured with a variety of
techniques, including Electronic Distance Meters (EDM), the Global Positioning System (GPS),
precise leveling surveys, strainmeters, and tiltmeters. EDMs use lasers to accurately measure
changes in distance between benchmarks (fixed points) with repeated measurements. GPS makes
use of satellites orbiting the Earth to determine and track the locations of points. Strainmeters
and tiltmeters are used to monitor subtle changes in shape of the ground surface.
Q: How are volcanic gases measured?
A: Instruments to measure sulfur dioxide and carbon dioxide can be mounted in aircraft to
determine the quantity of gas being emitted on a daily basis. Such instruments can also be used
in a ground-based mode. An instrument that detects carbon dioxide can be installed on a volcano
and configured to send data continuously via radio to an observatory. Sulfur dioxide in volcanic
clouds can also be measured from space with instruments aboard satellites
Q: What else do scientists measure at volcanoes?
A: Field observations by experienced volcanologists go hand in hand with more sophisticated
equipment and techniques to form a complete system for monitoring volcanoes. Field
observations may include water temperature and pH (acidity) measurements, or observations of
ground cracking and new areas of avalanching rocks. An experienced observer can integrate
many different types of data on the spot and design simple measurements to further assess the
significance of volcanic unrest. There is no substitute for well-trained, experienced observers
when trying to figure out how a volcano will behave.
About U.S. Volcanoes
There are over 160 U.S. volcanoes that have erupted in the
past 10,000 years (18 are in California). Listed below are
many of our monitored volcanoes with links to additional
information. Over the next few years, we will be updating
our volcano pages to provide links to images, publications,
hazard assessments, and monitoring data.
Alphabetical partial list of U.S. Volcanoes
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Agrigan - Mariana Islands, Mariana Islands
Ahyi - Mariana Islands, Mariana Islands
Akutan - Alaska, Aleutians
Alamagan - Mariana Islands, Mariana Islands
Amak - Alaska, Alaska Peninsula
Amboy - Western US, CA
Amchixtam Chaxsxii - Alaska, Aleutians
Amukta - Alaska, Aleutians
Anatahan - Mariana Islands, Mariana Islands
Aniakchak - Alaska, Alaska Peninsula
Asuncion - Mariana Islands, Mariana Islands
Atka - Alaska, Aleutians
Augustine - Alaska, Cook Inlet-South Central
Bald Knoll volcanic field - Western US, UT
Belknap Shield Volcano - Western US, OR
Big Cave - Western US, CA
Black Peak - Alaska, Alaska Peninsula
Black Rock Desert volcanic field - Western US, UT
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Blue Lake Crater - Western US, OR
Bobrof - Alaska, Aleutians
Bogoslof - Alaska, Aleutians
Brushy Butte - Western US, CA
Buldir - Alaska, Aleutians
Buzzard Creek - Alaska, Interior Alaska
Carlisle - Alaska, Aleutians
Carrizozo - Western US, NM
Cerberus, Mt - Alaska, Alaska Peninsula
Chagulak - Alaska, Aleutians
Chiginagak - Alaska, Alaska Peninsula
Cinnamon Butte - Western US, OR
Clear Lake - Western US, CA
Cleveland - Alaska, Aleutians
Coso Volcanic Field - Western US, CA
Crater Lake - Western US, OR
Craters of the Moon volcanic field - Western US, ID
Dana - Alaska, Alaska Peninsula
Davidof - Alaska, Aleutians
Davis Lake - Western US, OR
Denison - Alaska, Alaska Peninsula
Devils Garden - Western US, OR
Diamond Craters - Western US, OR
Dotsero - Western US, CO
Douglas - Alaska, Alaska Peninsula
Duncan Canal - Alaska, Southeast Alaska
Dutton - Alaska, Alaska Peninsula
Eagle Lake Field - Western US, CA
East Cape volcano - Alaska, Aleutians
Edgecumbe - Alaska, Southeast Alaska
Emmons Lake Volcanic Center - Alaska, Alaska Peninsula
Esmeralda Bank - Mariana Islands, Mariana Islands
Falling Mtn - Alaska, Alaska Peninsula
Farallon de Pajaros - Mariana Islands, Mariana Islands
Fisher - Alaska, Aleutians
Four Craters Lava Field - Western US, OR
Fourpeaked - Alaska, Alaska Peninsula
Frosty - Alaska, Alaska Peninsula
Gareloi - Alaska, Aleutians
Gilbert - Alaska, Aleutians
Glacier Peak - Western US, WA
Golden Trout Creek - Western US, CA
Gordon - Alaska, Wrangell Volcanic Field
Great Sitkin - Alaska, Aleutians
Griggs - Alaska, Alaska Peninsula
Guguan - Mariana Islands, Mariana Islands
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Haleakala - Hawaii and Pacific Ocean, HI
Hayes - Alaska, Cook Inlet-South Central
Hells Half Acre volcanic field - Western US, ID
Herbert - Alaska, Aleutians
Hualalai - Hawaii and Pacific Ocean, HI
Iliamna - Alaska, Cook Inlet-South Central
Indian Heaven - Western US, WA
Ingakslugwat Hills - Alaska, Southwest Alaska
Inyo Craters - Western US, CA
Iskut-Unuk River cones - Alaska, Southeast Alaska
Jackies Butte - Western US, OR
Jordan Craters - Western US, OR
Kagamil - Alaska, Aleutians
Kaguyak - Alaska, Alaska Peninsula
Kanaga - Alaska, Aleutians
Kasatochi - Alaska, Aleutians
Katmai - Alaska, Alaska Peninsula
Khvostof - Alaska, Aleutians
Kialagvik - Alaska, Alaska Peninsula
Kilauea - Hawaii and Pacific Ocean, HI
Kiska - Alaska, Aleutians
Klawasi Group - Alaska, Wrangell Volcanic Field
Kookooligit Mountains - Alaska, Bering Sea
Korovin - Alaska, Aleutians
Kukak - Alaska, Alaska Peninsula
Kupreanof - Alaska, Alaska Peninsula
Lassen Volcanic Center - Western US, CA
Lavic Lake - Western US, CA
Little Sitkin - Alaska, Aleutians
Long Valley Volcanic Center - Western US, CA
Lo`ihi - Hawaii and Pacific Ocean, HI
Mageik - Alaska, Alaska Peninsula
Makushin - Alaska, Aleutians
Mammoth Mountain - Western US, CA
Markagunt Plateau volcanic field - Western US, UT
Martin - Alaska, Alaska Peninsula
Maug Islands - Mariana Islands, Mariana Islands
Mauna Kea - Hawaii and Pacific Ocean, HI
Mauna Loa - Hawaii and Pacific Ocean, HI
Medicine Lake Volcano - Western US, CA
Moffett - Alaska, Aleutians
Mono Lake Volcanic Field - Western US, CA
Mount Adams - Western US, WA
Mount Bachelor - Western US, OR
Mount Baker - Western US, WA
Mount Hood - Western US, OR
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Mount Jefferson - Western US, OR
Mount Rainier - Western US, WA
Mount Shasta - Western US, CA
Mount St. Helens - Western US, WA
Mount Washington - Western US, OR
Newberry Volcano - Western US, OR
North Sister Field - Western US, OR
Novarupta - Alaska, Alaska Peninsula
Nunivak Island - Alaska, Southwest Alaska
Okmok - Alaska, Aleutians
Pagan - Mariana Islands, Mariana Islands
Pavlof - Alaska, Alaska Peninsula
Pavlof Sister - Alaska, Alaska Peninsula
Recheshnoi - Alaska, Aleutians
Redoubt - Alaska, Cook Inlet-South Central
Roundtop - Alaska, Aleutians
Ruby - Mariana Islands, Mariana Islands
San Francisco Peaks volcanic field - Western US, AZ
Sand Mountain Field - Western US, OR
Sanford - Alaska, Wrangell Volcanic Field
Santa Clara volcanic field - Western US, UT
Sarigan - Mariana Islands, Mariana Islands
Seguam - Alaska, Aleutians
Segula - Alaska, Aleutians
Semisopochnoi - Alaska, Aleutians
Shishaldin - Alaska, Aleutians
Shoshone Lava Field - Western US, ID
Snowy - Alaska, Alaska Peninsula
South Sister - Western US, OR
Spurr - Alaska, Cook Inlet-South Central
Squaw Ridge Lava Field - Western US, OR
St. Michael - Alaska, Southwest Alaska
St. Paul Island - Alaska, Bering Sea
Steamboat Springs - Western US, NV
Steller - Alaska, Alaska Peninsula
Stepovak Bay 2 - Alaska, Alaska Peninsula
Stepovak Bay 3 - Alaska, Alaska Peninsula
Stepovak Bay 4 - Alaska, Alaska Peninsula
Submarine 002 - Alaska, Aleutians
Submarine 005 - Alaska, Aleutians
Supply Reef - Mariana Islands, Mariana Islands
Table Top Mtn - Alaska, Aleutians
Takawangha - Alaska, Aleutians
Tana - Alaska, Aleutians
Tanaga - Alaska, Aleutians
Tlevak Strait-Suemez Island - Alaska, Southeast Alaska
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Trident - Alaska, Alaska Peninsula
Tumble Buttes - Western US, CA
Twin Buttes - Western US, CA
Ubehebe Craters - Western US, CA
Ugashik-Peulik - Alaska, Alaska Peninsula
Uinkaret volcanic field - Western US, AZ
Ukinrek Maars - Alaska, Alaska Peninsula
Uliaga - Alaska, Aleutians
Unnamed (near Ukinrek Maars) - Alaska, Alaska Peninsula
Valles Caldera - Western US, NM
Veniaminof - Alaska, Alaska Peninsula
Vsevidof - Alaska, Aleutians
Wapi Lava Field - Western US, ID
West Crater - Western US, WA
Westdahl - Alaska, Aleutians
Wide Bay cone - Alaska, Aleutians
Wrangell - Alaska, Wrangell Volcanic Field
Yantarni - Alaska, Alaska Peninsula
Yellowstone - Western US, WY
Yunaska - Alaska, Aleutians
Zuni-Bandera volcanic field - Western US, NM
Cascade Range Volcanoes (California/Washington)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN
Activity Update: All volcanoes in the Cascade Range are at normal levels of background seismicity.
These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in
Washington State; Mount Hood, Mount Jefferson, Three Sisters, Newberry Volcano, and Crater Lake, in
Oregon; and Medicine Lake volcano, Mount Shasta, and Lassen Peak in northern California.
Mount St. Helens has been at Volcano Alert Level NORMAL (Aviation Color Code GREEN) since July
10, 2008. Recent Observations: Volcano seismicity has remained at background levels throughout the
week.
Long Valley Volcanic Center (California)
37.70°N 118.87°W, Summit Elevation 11122 ft (3390 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN
The automatic processing system detected seven earthquakes in the Long Valley area since the last
update at 9:29 AM on the 1st including magnitude 3.3 and 3.0 earthquakes at 1:13 AM and 7:11 AM,
respectively. All were located in the Sierra Nevada 10 miles SE of Mammoth Lakes (0.5 mile north of
Red Slate Mountain). The two magnitude 3 earthquakes likely produced perceptible shaking in the
Mammoth Lakes area.
The Long Valley Observatory (LVO) monitors and studies earthquakes, ground deformation, degassing,
and other types of geologic unrest in and around the Long Valley Caldera. The 15 by 30 km Long
Valley Caldera was formed during an eruption 760,000 years ago and is located 20 km south of Mono
Lake along the east side of the Sierra Nevada in east-central California. There have been multiple
smaller eruptions since the caldera-forming eruption with the most recent occurring 250 years ago in
Mono Lake at the north end of Mono-Inyo Craters volcanic chain. LVO is one of the five USGS
Volcano Observatories that monitor volcanoes within the United States for science and public safety.
Lassen Volcanic Center (California)
Current Update, last updated Mar 19, 2009 07:29 PDT:
Information Statement for the recent March 17-19, 2009, Lassen Peak swarm activity
A series of small earthquake swarms have occurred beneath the south flank of Lassen Peak in Lassen
Volcanic National Park over the last three days. This activity began at 3:00 AM (PDT) on March 17 and
persisted through 8:16 AM on the 19th. Episodic swarm activity on the 17th through 4:10 AM on
the18th included some 48 earthquakes large enough to be located, the three largest of which had
magnitudes of M=2.1, 2.0, and 2.2. Activity resumed at 6:57 AM on the 19th producing 26 earthquakes
by 8:19 AM, the largest of which was a M=1.9. These earthquakes are centered at a depth of roughly 5
km beneath the surface and, in map view, form an elongated pattern extending from the vicinity of Eagle
Peak on southwest flank of Lassen Peak to the vicinity of Diamond Peak 3 km further to the southsouthwest.
Volcanic History Overview: The Lassen volcanic center consists of the andesitic Brokeoff
stratovolcano SW of Lassen Peak, a dacitic lava dome field, and peripheral small andesitic shield
volcanoes and large lava flows, primarily on the Central Plateau NE of Lassen Peak. A series of
eruptions from Lassen Peak from 1914 to 1917 marks the most recent eruptive activity in the southern
Cascade Range. Activity spanning 600,000 years began with construction of Brokeoff stratovolcano.
Beginning 400,000 years ago activity shifted to the north flank of Brokeoff, where episodic, more silicic
eruptions produced a field of a dozen dacitic lava domes including Bumpass Mountain, Mount Helen,
Ski Heil Peak, and Reading Peak. At least 12 eruptive episodes took place during the past 100,000 years,
with Lassen Peak being constructed about 28,000 years ago. The Chaos Crags dome complex was
constructed about 1100-1000 years ago north of Lassen Peak. The Cinder Cone complex NE of Lassen
Peak was erupted in a single episode several hundred years before present and is considered part of the
Lassen volcanic center (Clynne et al., 2000). The 1914-1917 eruptions of Lassen Peak began with
phreatic eruptions and included emplacement of a small summit lava dome, subplinian explosions,
mudflows, and pyroclastic flows.
Name______________________________
Alaska Vocano Erupts
Each question is worth 5 points. For full credit, you must answer in complete
sentences and include all appropriate information. Explain your answers!
Continue on the back if you need more room.
1. Why is volcanic ash hazardous?
2. What other dangers can an eruption cause?
3. Explain the four Alert Levels and color codes:
4. How high has ash from Mount Redoubt risen?
5. How does the U.S. Geological Survey know when an eruption is likely? Please give a
complete explanation.
6. What percentage of U.S. vocanoes are considered to be high or very high threats?
7. In which 5 states does the USGS continuously monitor vocanic activity?
8. How many volcanoes are there in Arizona? How many in New Mexico?
9. Where is the Long Valley Caldera? When was it formed?
10. When did the most recent eruptions at the Lasssen Volcanic Center occur?