Mount Pinatubo

Mount Pinatubo is an active <a href="/facts/Stratovolcano/7xW98Mye">stratovolcano</a> in the <a href="/facts/Zambales_Mountains/gzvkgTvc">Zambales Mountains</a> in <a href="/facts/Luzon/dJNpzhEM">Luzon</a> in the <a href="/facts/Philippines/ARpmxXQV">Philippines</a>. Located on the <a href="/facts/Tripoint/j9IFVW6w">tripoint</a> of <a href="/facts/Zambales/hsV6x8bA">Zambales</a>, <a href="/facts/Tarlac/HH5pw0hL">Tarlac</a> and <a href="/facts/Pampanga/JmKPMHtc">Pampanga</a> provinces, most people were unaware of its eruptive history before the pre-eruption volcanic activity in early 1991. Dense <a href="/facts/Forest/RnMtb31v">forests</a>, which supported a population of several thousand indigenous <a href="/facts/Aeta_people/hMK1NMm5">Aetas</a>, heavily <a href="/facts/Erosion/gaGJXy0W">eroded</a> and obscured Pinatubo.
Pinatubo is known for its <a href="/facts/Volcanic_Explosivity_Index/jN8HWRM9">VEI</a>-6 <a href="/facts/1991_eruption_of_Mount_Pinatubo/8yhb1Y9n">eruption on June 15, 1991</a>, the second-largest terrestrial eruption of the 20th century after the 1912 eruption of <a href="/facts/Novarupta/38H6z38y">Novarupta</a> in <a href="/facts/Alaska/LlDNr2uR">Alaska</a>. The eruption coincided with <a href="/facts/Typhoon_Yunya_(1991)/AsJQqQzQ">Typhoon Yunya</a> making landfall in the Philippines, which brought a dangerous mix of ash and rain to nearby towns and cities. Early predictions led to the evacuation of tens of thousands of people, saving many lives. The eruption severely damaged surrounding areas with <a href="/facts/Pyroclastic_surge/lkUfm0Ux">pyroclastic surges</a>, <a href="/facts/Pyroclastic_fall/rfdfEjbX">pyroclastic falls</a>, and later, flooding <a href="/facts/Lahar/WM2kUufP">lahars</a> caused by rainwater re-mobilizing volcanic deposits. This destruction affected infrastructure and altered river systems for years. Minor <a href="/facts/Lava_dome/a3E6LnUJ">dome</a>-forming eruptions inside the caldera continued from 1992 to 1993.
The 1991 eruption had worldwide effects. It released roughly 10 <a href="/facts/1000000000_(number)/Ij1fl5Q7">billion</a> <a href="/facts/Tonne/gMymLmWv">tonnes</a> (1.1×1010 <a href="/facts/Short_ton/b2fcrxHq">short tons</a>) or 10 km3 (2.4 cu mi) of magma, bringing large amounts of minerals and toxic metals to the surface. It also released 20 million tonnes (22 million short tons) of <a href="/facts/Sulfur_dioxide/jDK1fIDs">SO2</a>. It ejected more <a href="/facts/Particulate/RleGr5E6">particulate</a> into the <a href="/facts/Stratosphere/taBra67V">stratosphere</a> than any eruption since <a href="/facts/Krakatoa/DQHgfyqx">Krakatoa</a> in 1883. In the following months, aerosols formed a global layer of <a href="/facts/Sulfuric_acid/Wom6fymJ">sulfuric acid</a> haze. Global temperatures dropped by about 0.5 °C (0.9 °F) in the years 1991–1993, and <a href="/facts/Ozone_depletion/ssGWpcx3">ozone depletion</a> temporarily increased significantly.

Mount Pinatubo open-in-new

Mount Pinatubo