MT. PINATUBO VOLCANO
Cycle B
Earth-o-nauts
I.
Event > Atmosphere > Lithosphere > Hydrosphere > Lithosphere
The pyroclastic flow can engulf surrounding villages in hot, poisonous gases, rock and
ash. The violent eruption brought about changes to river ways by changing the flow of
water in the area. The 1991 eruption occurred during the monsoon season causing the
river to flow down many paths causing extensive damage changes to the landscape. (1)
1. U.S. Geological Survey. “Heavy Rain Leads to Erosion and Lahars.”
USGS. Sept. 30, 1999. <
http://volcanoes.usgs.gov/Hazards/What/Lahars/RainLahar.html >.
II.
Event > Hydrosphere > Lithosphere > Atmosphere
Dangerous steam escaped from the flowing lahars into the surrounding air. (1)
1. U.S. Geological Survey. “Heavy Rain Leads to Erosion and Lahars.”
USGS. Sept. 30, 1999. <
http://volcanoes.usgs.gov/Hazards/What/Lahars/RainLahar.html >.
III.
Event > Hydrosphere > Lithosphere > Biosphere
The explosion of the volcanic eruptions disrupted the balance within the groundwater
system of the surrounding areas. The time to get farm land back took longer than
expected due to the disruption. (2) The ground water of the area was heated. (3)
2. Shigenobu, Hiraide, and et al. “Initial Exploration for Ground Water in Lahar
Disaster Area, Mt. Pinatubo, Philippines.” Journal of the Japan Society of
Engineering Geology. 2001. < http://sciencelinks.jp/jeast/article/200205/000020020502A0090880.php >.
3. Love, Jamie. “The Montserrat Volcano.” Merlin Science. 15 January
1998 < http://www.synapses.co.uk/science/mvolcano.html >.
IV.
Event > Lithosphere > Hydrosphere > Biosphere
When an eruption ceases and a volcano becomes inactive, the underground magma
chamber remains hot for hundreds and thousands of years. Groundwater in the vicinity
that comes in contact with the cooling, but still-hot magma chamber is heated and rises to
the surface along rock fractures and forms thermal springs, fumaroles or geysers. In
Iceland, Italy, and New Zealand where thermal springs are in abundance, people use the
springs to heat homes and businesses. (4)
4. Mattox, Steve. “Mt. Pinatubo, Philippines – 1991”. Volcanic Gases. <
http://volcano.und.edu/vwdocs/Gases/pinatubo.html >.
V.
Event > Hydrosphere > Lithosphere >Biosphere
In some circumstances, deep circulating heated groundwater dissolves minerals from the
cooling magma. The minerals precipitate out of the hydrothermal water depositing
themselves in any openings they encounter in the surrounding rock, filling cracks and
sometimes replacing rocks themselves. The mineral deposits are not vast in extent but
are quite mineral rich. The gold and silver deposits in parts of Colorado and Nevada are
remains of hydrothermal deposits. Little did the early prospectors of the Gold Rush
realize that their riches were the result of such amazing geologic processes. (5)
5. Mattox, Steve. “Volcanic Gases: Average Compositions and Minor or Trace
Gases”. Volcanic Gases. <
http://volcano.und.edu/vwdocs/Gases/pinatubo.html >.
VI.
Event > Atmosphere > Hydrosphere
Data shows that large volcanic eruptions can temporarily cool Earth’s climate. Some
scientists now propose that this change in climate lowers sea level worldwide. The
cooling of the climate is a response to sunlight being reflected off the tiny particles and
droplets of condensed gases ejected by large volcanic eruptions. The climate then cools
in response to less radiation reaching Earth’s surface to warm it. (John A. Church,
oceanographer at the Commonwealth Scientific and Industrial Research Organization in
Hobart, Tasmania) The deflection of the sun’s rays can cause a cooling of earth’s
temperature below its normal temperature for months. The cooling of air temperature in
turn will cool ocean temperatures. The water contracts as it cools and results in a drop in
sea level. Church came to this conclusion when he analyzed tide data from around the
world, ocean temperature and salinity measurements gathered by ships, climate models
that show interaction of atmosphere and ocean. His analysis showed that after every
major 20th century eruption, the oceans cooled subtly for about 18 months, sea level
dropped several millimeters on average. Once the volcanic materials in the atmosphere
had settled out, the oceans warmed, expanded, and sea level recovered in approximately
10 years. (6)
6. Perkins, Sid. “Volcanic Suppression: major eruptions can reduce sea level”.
Science News. Nov. 5, 2005. <
http://findarticles.com/p/articles/mi_m1200/is_19_168/ai_n15928102 >.
VII. Event>Atmosphere>Biosphere
When volcanoes erupt violently as Mt. Pinatubo did in 1991, the force of the eruption
propels large amounts of ash into the stratosphere. The ash particles are harmful to
engines of jet aircraft. That is why when Mt. Pinatubo erupted; commercial aircraft were
warned about the danger and most avoided the area. However, some “jets flying far to
the west of the Philippines encountered ash and sustained about $100 million in damages.
(1) This damage to the aircrafts and rerouting of planes would have caused flight delays
and the need for more fuel. These events would have cost the airlines money well over
the $100 million needed to just repair/replace the engines. These costs were probably
passed on to the customers in the way of higher ticket costs.
7. http://pubs.usgs.gov/fs/1977/fs113-97
VIII. Event>Atmosphere>Hydrosphere>Biosphere
Mount Pinatubo ejected between 15 and 30 million tons of sulfur dioxide gas. Sulfur
dioxide in the atmosphere mixes with water and oxygen in the atmosphere to become
sulfuric acid, which in turn triggers ozone depletion. (8) Acid rain harms or kills
individual fish, reduces fish population numbers, completely eliminates fish species from
a waterbody, and can decrease biodiversity. As acid rain flows through soils in a
watershed, aluminum is released from soils into the lakes and streams located in that
watershed. So, as pH in a lake or stream decreases, aluminum levels increase. Both low
pH and increased aluminum levels are directly toxic to fish. In addition, low pH and
increased aluminum levels cause chronic stress that may not kill individual fish, but lead
to lower body weight and smaller size and makes fish less able to compete for food and
habitat. (9)
8. http://geography.about.com/od/globalproblemsandissues/a/pinatubo.htm
9. http://www.epa.gov/acidrain/effects/surface_water.html#a1
IX. Atmosphere>Lithosphere>Biosphere<Lithosphere
The most catastrophic lithospheric impact of Pinatubo is the ash it produced into the
atmosphere. (10) Ash and particulate matter in the air was not limited to the site of the
volcano. As ash covers the soil, one of two things can happen. The soil becomes sterile
because ash coverage deprives the soil of oxygen. When this happens, plant life dies and
so do the microorganisms and decomposers in the soil. (11) When this happens, the soil
becomes sterile. Until weathering breaks down the ash, or erodes it away, plant growth
and development is stymied as is regular workings of the Nitrogen Cycle in the soil. Ash
is also known to add minerals to soil that are beneficial to plant growth and development.
So I suspect that it depends on the depth of the ash deposited and the size of the particles
as to how quickly the soil is able to recover from ash deposition as result of a volcano.
(12)
10. http://volcanoes.usgs.gov/ash/todo.html
11. http://volcanoes.usgs.gov/ash/agric/index.html#pasture
12. http://volcano.und.edu/vwdocs/frequent_questions/grp4/question440.html
X.
Lithosphere>Atmosphere>Hydrosphere
The volcanic eruption of Pinatubo caused the heating of the lower tropical stratosphere
due to the aerosols produced from the gaseous eruptions. This raised the temperature and
as a result, changed atmospheric wind patterns in the troposphere which had a large
impact on winter temperatures. The winter of 1991-1992 the temperature in North
America, Europe, and Siberia was warmer than usual but in Alaska, Greenland, the
Middle East, and China, it was colder than normal. In fact, it even snowed in Jerusalem
that year. (13) This is supposed to very abnormal.
13.
http://climate.envsci.rutgers.edu/pdf/EGECPinatubo.pdf