Lake Pinatubo () is the

summit A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topographic terms acme, apex, peak (mountain peak), and zenith are synonymous. The term (mountain top) is generally used only for ...

crater lake of

Mount Pinatubo Mount Pinatubo is an active stratovolcano in the Zambales Mountains in Luzon in the Philippines. Located on the tripoint of Zambales, Tarlac and Pampanga provinces, most people were unaware of its eruptive history before the pre-eruption volc ...

formed after its climactic eruption on June 15, 1991. The lake is located in the

Zambales Mountains The Zambales Mountains is a mountain range in western Luzon. The mountains spread along a north-south axis, separating Luzon's central plain from the South China Sea. The range extends into five Provinces of the Philippines, provinces: Zambales, ...

, in Botolan,

Zambales Zambales, officially the Province of Zambales (; ; ; ; ), is a Provinces of the Philippines, province in the Philippines located in the Central Luzon Regions of the Philippines, region. Its capital is Iba, Zambales, Iba, which is located in t ...

, near the boundaries of

Pampanga Pampanga, officially the Province of Pampanga (; ; ), is a province in Central Luzon in the Philippines. Lying on the northern shore of Manila Bay, Pampanga is bordered by Tarlac to the north, Nueva Ecija to the northeast, Bulacan to the east, ...

and

Tarlac Tarlac, officially the Province of Tarlac (; ; ; ; ), is a landlocked Provinces of the Philippines, province in the Philippines located in the Central Luzon Regions of the Philippines, region. It had a population of 1,503,456 people according to ...

provinces A province is an administrative division within a country or state. The term derives from the ancient Roman , which was the major territorial and administrative unit of the Roman Empire's territorial possessions outside Italy. The term ''provi ...

in the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

. It is about northwest of the capital city of

Manila Manila, officially the City of Manila, is the Capital of the Philippines, capital and second-most populous city of the Philippines after Quezon City, with a population of 1,846,513 people in 2020. Located on the eastern shore of Manila Bay on ...

. While one paper by researchers from Japan suggested a depth of , more detailed research suggests that is more accurate.

Geology

Mount Pinatubo's volcanic activity has followed a cycle: centuries of repose terminated by a caldera-forming eruption with large pyroclastic flows; a post-eruption aftermath of rain-triggered lahars in surrounding drainages and dome-building that fills the caldera; and then another long quiescent period. During and after the eruptions, lahars descending along volcano channels may block tributaries from watersheds beyond Pinatubo, creating natural lakes. Geophysical evidence shows that there were at least two ancient lakes in the Mapanuepe River valley in the southwestern part of the volcano.

Origin

The climactic 1991 eruption of Mount Pinatubo destroyed the volcano's original summit. In its place is a diameter

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

, the center of which is offset northward from the pre-eruption summit. It was created from the collapse of the volcano's summit on June 15, during the period of abundant large earthquakes in response to withdrawal of a large volume of magma from the reservoir beneath the volcano. By early September 1991, a shallow lake formed. The high precipitation rate of the area led to a rapid transition from a small and hot acidic lake to a large lake with near-ambient temperature and pH.

Legend

The mountain range wherein the volcano is located is inhabited by the indigenous

Aeta Aeta (Ayta ), Agta and Dumagat, are collective terms for several indigenous peoples who live in various parts of Luzon islands in the Philippines. They are included in the wider Negrito grouping of the Philippines and the rest of Southeast A ...

s. An old Aeta legend tells of a lake that once existed in the site, most probably the latter of the two ancient crater lakes, and of a great explosion that destroyed it.

Lake drainage

Risk of flash floods in the communities found in the vicinity of the recently dormant volcano is imminent because of a danger of the caldera collapsing due to water pressure and a long-term increase in the water level of ~1 m/month. Experts had feared the weight of the water could have breached the crater walls and flooded the homes of up to 40,000 people in and around the small coastal town of

Botolan Botolan, officially the Municipality of Botolan, is a municipality in the province of Zambales, Philippines. According to the 2020 census, it has a population of 66,739 people. The municipality was founded by Spanish Governor-General Juan de S ...

, located 25 miles from the volcano. In September 2001, residents of Botolan and nearby areas were sent to evacuation centers as a precaution from a possible deluge of mud and water. The Philippine government ordered a controlled draining of the lake and had authorities dig a 5m-wide channel from the edge of the volcano's crater, draining about a quarter of the lake's volume and diverting the excess lakewater into local rivers. Existing

lahar A lahar (, from ) is a violent type of mudflow or debris flow composed of a slurry of Pyroclastic rock, pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a valley, river valley. Lahars are o ...

canyons A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency t ...

serve as water drainage paths to surrounding

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

s and creeks, the largest of which is the Bucao River. In 2002, accumulated rainwater in the lake rose to dangerous levels during the rainy monsoon season, breached the artificial drainage canal, and triggered mild lahar flows in the area.

Tourism

The lake is described as "a wide jewel of blue and green"C. Tejero, "Pinatubo 10 Years After : Beyond the valley of lahar", ''Philippine Daily Inquirer'', April 29, 2001 and is now a popular bush walking destination, mostly frequented by

mountaineer Mountaineering, mountain climbing, or alpinism is a set of outdoor activities that involves ascending mountains. Mountaineering-related activities include traditional outdoor climbing, skiing, and traversing via ferratas that have become sports ...

s and adventure-seekers. Until improvements were made, a trip to the summit involved either days of hiking or hours of 4-wheel vehicle travel followed by a 2-hour hard hike. Eventually, a trail called the ''Skyway'' was made that allows

four-wheel drive A four-wheel drive, also called 4×4 ("four by four") or 4WD, is a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer case pr ...

vehicles a shorter route to a drop off point to trek to the crater. The skyway shortened the route from a ride 2 hours and 9 minutes long to an hour's trek.

Notes

Sources

* *

References

PHIVOLCS – Pinatubo Data Update
(retrieved: March 5, 2009)

(retrieved: March 10, 2009)
BBC News Online
(retrieved: March 26, 2009) * Newhall, C.G. and Punongbayan, R.S., ''Fire and Mud: Eruptions and Lahars of Mount Pinatubo, Philippines'', Philippine Institute of Volcanology and Seismology, Quezon City and University of Washington Press, Seattle and London, 1126 pages, 1996. (retrieved: March 10, 2009) * BBC NEWS World: Asia-Pacific, Friday, September 7, 2001, 12:52 GMT 13:52 UK (retrieved: March 10, 2009) * BBC NEWS World: Asia-Pacific, Friday, September 7, 2001, 21:25 GMT 22:25 UK (retrieved: March 12, 2009)

External links

* Geographic data related t
Lake Pinatubo
at

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{{Central Luzon attractions Pinatubo Landforms of Pampanga Landforms of Tarlac Landforms of Zambales Tourist attractions in Pampanga Zambales Mountains Mount Pinatubo