Guagua Pichincha, Ecuador
Guagua
Pichincha is a stratovolcano located 7 miles (11 km) from Ecuador's
capital city of Quito. It has been the site of 25 historic eruptions.
The volcano's last magmatic eruption occurred in 1660. This was an explosive
eruption, and showered Quito with ash. All eruptions since that time
have been phreatic. One such eruption, in 1993, killed two volcanologists
working on the volcano's summit.
December 3, 1999
- The Guagua Pichincha Volcano erupted
on 26 November, and a column of ash rose nine miles (14 km) into the
sky. The volcano erupted again on 29 November and produced a column
of ash and gas six miles high. The yellow alert for Guagua Pichincha
remains in effect.
- November 26, 1999
- On 24 November, the Guagua Pichincha
Volcano once again erupted and sent a column of ash into the sky that
was 10 km high. Local schools and the airport have been closed. The
volcano is still under a yellow alert.
- November 18, 1999
- On 17 November, the Guagua Pichincha
Volcano erupted and sent smoke and ash skyward 16,400 feet. The ash
eventually settled on the city of Quito. The alert level of the Guagua
Pichincha Volcano remains at yellow.
- November 10, 1999
- The yellow alert is still in effect for
the Guagua Pichincha Volcano. Seismic events between 21 October and
4 November 1999 have reached their highest peak since the activity began
15 months ago. Three to four thousand events per day have been registered.
On 9 November, a magmatic explosion occurred and ash coated the city
of Quito. An orange alert is in effect for the town of Lloa and the
surrounding villages.
- November 8, 1999
- On 29 October, there were no explosions
in the past 24 hours, but numerous hybrid and long period earthquakes
did occur. A gas column rose to a height of ~1,200 m. A new dome is
present and the fumarolic plume rises to less than 100 m.
- October 12, 1999
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(View from the south end of the crater - 12 noon, August 29, 1999.)
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- A lava dome containing huge blocks of
a very viscous material is present at the western edge of the crater.
Volcanic material collapses to the west producing pyroclastic flows
and ash clouds. The process may continue for years. On 4 October, the
volcano was returned to a Yellow Alert state. The Orange Alert is still
effective for the town of Lloa. The citizens remain in temporary shelters.
- October 8, 1999
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(View from the south end of the crater - 12 noon, August 29, 1999.)
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- On the morning of 7 October, the Guagua
Pichincha Volcano erupted three times sending ash and boiling water
skyward. A spectacular mushroom shaped cloud rose ~12 km (~7.5 miles)
above the volcano. And elderly man died from respiratory complications,
and other people suffered breathing difficulties and even loss of consciousness.
- October 6, 1999
- On 4 October, the Guagua Pichincha Volcano
alert was downgraded to yellow in view of the decreased seismic activity.
The Geophysical Institute of the National Polytechnic School monitors
the volcano. During the past 12 months, the Institute has received support
from international experts from Canada, Colombia, France, Italy, and
the United States. Phreatic and ash explosions are more frequent. Deformation
of the dome has been observed and magmatic products are now present
in the volcanic material expulsed. On 5 October, an ash cloud rose over
19,500 meters (~64,000 feet) and began to move eastward covering parts
of Quito. Quito's airport and school remain closed. Lloa, the town with
the highest risk area, has been evacuated to shelters.
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- October 4, 1999
- Rockfalls, increasing seismicity, and
the growth or deformation of the dome continues. In the past 24 hours,
there were 1403 long period earthquakes and 42 hybrid earthquakes. On
the morning of 1 October, aerial observations found very strong fumarolic
activity (plumes to 1500 m in height) from the dome in the caldera.
However, there was a low value of 160 tons/day of SO2 flux.
- September 30, 1999
- The Guagua Pichincha activity continues,
and another ash eruption occurred on 28 September at 2250. Ash fell
to the South. The current level of alert is ORANGE.
- September 28, 1999
- On 27 September, an orange alert was
issued for the eruption of Guagua Pichincha Volcano. Magma was found
to be 2 km below the dome.
- September 7, 1999
- On the 3 and 4 of September, the Guagua
Pichincha Volcano exploded. Clouds of gas and ash spewed 3.4 miles into
the sky. Seismologists warn that further activity could threaten Ecuador's
capital city of Quito.
- August 27, 1999
- On 16 August, a small phreatic eruption
occurred at the Guagua Pichincha Volcano, followed by one hour of tremor.
Eruptions on the 10-12 August have left a thin covering of ash on vegetation
west of the dome. On 23 August, another small phreatic eruption occurred.
On 24 August, there was a large explosion and a mushroom-shaped cloud
rose to 6 km. a.s.l. Two smaller events followed.
- August 12, 1999
- On 7 August, the Guagua Pichincha Volcano
produced a small phreatic eruption, followed by a 40 minute tremor.
Fumarolic activity is reduced in the 1981 and July 6 craters.
- August 6, 1999
- On 2 August, a strong phreatic eruption
occurred at the Guagua Pichincha Volcano. An ash column rose 2 km from
the new crater on the W part of the dome.
- July 26, 1999
- The Guagua Pichincha Volcano erupted
on 14 July. The eruption was followed by six hours of tremors.
- July 6, 1999
- During the month of June, Guagua Pichincha
had 16 phreatic eruptions, two powerful eruptions (11 and 17 June),
and two moderate eruptions (4 and 9 June). A total of 160 volcano-tectonic
earthquakes were registered in June.
- June 22, 1999
- As of 17 June 1999, the Guagua Pichincha
Volcano is experiencing a period of intense fumarolic activity with
occasional phreatic eruptions. On the 18th, fumarolic plumes were rising
300-400m.
- June 16, 1999
- On 5 June 1999, a phreatic eruption occurred
and another on 6 June. Moderate fumarolic activity continues at the
dome with gas columns rising 100m.
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- January 10, 1999
- An eruption at Guagua Pichincha occurred
on January 10, sending huge clouds of ash and steam up to 2,400 feet
(800 m) over the Ecuadorian capital of Quito. Local authorities issued
a low-level alert. They warn that acid rain could threaten the area
if eruptions continue.
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- October 7, 1998
- Over 30 phreatic explosions have occurred
at Guagua Pichincha over the last several days. The largest explosions
to date occurred on October 5. About two to three explosions occurred
on that day. A yellow alert has been declared at the volcano, with the
possibility of larger eruptions in the near future. Upon hearing this
alert, residents of Quito ran to buy gas masks and canned food. Scientists,
however, say that Pichincha volcano, located between Guagua Pichincha
and Quito, would block any lava from reaching the capital city. The
city could, however, be showered by volcanic ash.
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