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Mt. pinatubo (LK): Biosphere

Mt. Pinatubo Cycle A1: Individual response: Biosphere

 Prior Knowledge:

1.    I know that volcanic eruptions can release various gases and ash into the atmosphere that can change weather patterns globally, which the Pinatubo eruption did. 

2.    People, other animals including wildlife, structures, vegetation, and farmland can be destroyed when located in close proximity to the blast.  This loss can happen even after the initial blast, and take years to rebuild/ recover.

3.    The global weather changes from Pinatubo affected ozone levels in our atmosphere and enlarged the ozone hole over Antarctica.

4.    Although evacuation plans were in place, many people died form this eruption. 

Questions for the biosphere:

  1. How did the weather pattern changes affect the biosphere, including crop production, marine life, vegetation, and land use?
  2. How did human collaboration and support between governmental agencies provide preventative support during the event?
  3. How did the combination of the event (eruption) with the typhoon (Yunga) magnify the affects on the inhabitants in surrounding areas?

Biosphere description of Mt. Pinatubo:

Mt. Pinatubo is a volcano north of Manila on the Philippine island of Luzon, where the boarders of 3 different provinces meet.  The volcano was covered in dense forest prior to the eruption, which provided homes for the several thousand indigenous people called Aeta.

Since this volcano was highly eroded and covered with vegetation, many of the 30,000 people living in the villages surrounding the volcano did not even know that it existed.  The soil was very fertile, which allowed agriculture to thrive in the area as well as wildlife ecosystems. 

Source: wikipedia.com

Event Connections to the Biosphere:


The event kills plants and animals from the initial blast itself.  From falling material, burial from ash, burning, toxic gases released, reduction of light, and the encroachment of organisms that fled into other populated areas. Source: http://www.strategies.org/docs/essea_29oct/hil912/outline/wk3rdg2.html


Over 100,000 people became homeless form the eruption, as they lost their homes to the event. 2.1 million people affected by event: with job, food source, and/ or home being destroyed by event. Source: http://geography.about.com/od/globalproblemsandissues/a/pinatubo.htm

E> B

The initial volcanic events allow for the evacuation of 18,000 US military personnel from Clark Air Base, most of which are relocated back to the USA. Source: http://geography.about.com/od/globalproblemsandissues/a/pinatubo.htm


Event causes the loss of educational programs for children. Source: http://www.absoluteastronomy.com/topics/Mount_Pinatubo


Initial explosions create an alliance between the Philippines Institute of Volcanology and Seismology (PHIVOLCS) and the US Geological Survey, as they worked to convince people in the local area of the severity of the threat, prior to June 15th and established evacuation zones. Source: http://www.absoluteastronomy.com/topics/Mount_Pinatubo

E >B > E > B

Initial earthquakes and small explosions cause for a first wave of evacuations of approximately 5000 people in April 1991.  Earthquakes and explosions continued.  More evacuations were initiated beginning June 5th. Source: http://geography.about.com/od/globalproblemsandissues/a/pinatubo.htm

E + A>B

The major eruption on June 15th occurred while tropical storm/ typhoon Yunya was passing through the region (E + A).  The combination greatly compounded the destruction of property and loss of life in lahals, and heavy ash/ mud collapsing rooftops.  Source: http://en.wikipedia.org/wiki/1991_Pacific_typhoon_season#Typhoon_Yunya_.28Diding.29


Event causes many to be displaced in relocation camps.  Poor sanitation in relocation camps the deaths of hundreds. Source: http://www.absoluteastronomy.com/topics/Mount_Pinatubo


Agriculture in the region immediately surrounding the region is rendered infertile.  Farmers loose homes, food source, and careers. Source: http://www.absoluteastronomy.com/topics/Mount_Pinatubo 


Large volcanic eruption causes hazy atmosphere for extended period of time.  Haze in atmosphere allows for plants to photosynthesize more efficiently.  Plants absorb more carbon dioxide from atmosphere. Source: http://earthobservatory.nasa.gov/Newsroom/view.php?id=22098


Eruption puts large amounts of ash into air.  The ash lands in surrounding ocean waters.  Presence of hydrogen sulfide, and higher mixing of water temps, cause production of thick red algal blooms.  The algae smother coral below, by blocking out sunlight. Source: http://www.cotf.edu/ete/modules/coralreef/CRlitho.html