VOLCANOES
...s and property, and yet people continue to live near these forces. In addition to causing destruction, volcanic eruptions can even affect global politics and the fate of Clark Field, a U.S. Air Force Base, was a perfect example. Although disastrous, volcanoes supply many valuable resources. Basalt, a durable igneous rock, is used in our everyday road systems and pumice, another rock used in the process of making wood and metal polish. This rock is also used as a cleaning stone and for the use of cleaning our human bodies. Obsidian is another igneous rock that is formed and comes in a variety of colors and is especially valued as a semiprecious stone. Many of Africa’s diamond mines are located in old volcanic vents along with a large part of the world’s mineral ores such as copper, tin, and silver. The movement of the hot underground helps bring these minerals to the earth’s surface. If not for volcanic activity, many minerals would be buried beyond our reach. Volcanoes are also a big part of the solution to the world’s current energy shortage. They produce geothermal energy, which stands for “earth heat” and is a much cleaner natural power source. “The mysterious timing of the Mount Pinatubo eruption has been considered to be unusual for a number of reasons. Mount Pinatubo is considered to be the holiest by the Aeta peoples throughout the Philippines. The mountain is the home of Apona Mallari, also known as Bulan, the Moon God” (USGS, 2003). Before the eruption, the Pinatubo Ayta peoples had complained that authorities of Clark Air Force Base were drilling on their holy mount. It was not until after the signing of the extension agreement of the U.S. military bases, that Mount Pinatubo erupted, causing complete evacuations. Massive demonstrations against the renewal of the bases along with major media news coverage still could not change the minds of those in power. “The official day of the Philippine Republic is June 12, which even makes this story even more mysterious. It coincides with a particular cycle based on the founding of the republic. There are two shadowy planets in India’s astrology. They are known as Rahu and Ketu and actually, they are not planets at all, but points in space where eclipses occur. Rahu and Ketu were respectively the head and tail of a great dragon (USGS, 2003). The shadow cast made by this great serpent over the luminous orbs of the sun and moon was said to represent karma, the baggage from our past that effects our lives today” (USGS, 2003). The Philippines declared independence from Spain on June 12, 1898. Rahu and Ketu were about a degree from the same position when Mount Pinatubo erupted on June 12, 1991. In the same year, the Philippine American war broke out when the U.S. refused to recognize the independence of the island nation. “Some people question if Rahu and Ketu fulfilled their karmic duties on that day. Clark Air Base was completely destroyed by Mount Pinatubo’s eruption and was immediately closed. Subic Naval Base, which was another U.S. military base, was a far distance from the eruption sight, however just as the volcano began its eruptions, a typhoon came through the Philippines. A huge cloud of debris was ejected by the mountains making it impossible to fly and forced an immediate evacuation by the sea. The typhoon was believed to be mysterious in such a way that it did not follow its usual track. Normally the cyclone would come from southeast toward the northwest, but in this case it came from the northeast and passed over Clark Base and turned southwest toward Subic. Ultimately, the Philippine Senate decided against renewing Subic given the superstitious nature of many Filipinos” (USGS, 2003). “Mount Pinatubo ‘s 1991 eruption set off rumors that led the local people sifting through the fallen ash. What was thought to be diamonds spewing out of the volcano, turned out to be quartz crystals formed the hardening of magma inside the volcano”(Luhr, 1991, vol.354). Pumices from the June 6 through June 15 eruptions bore anhydrite. An enormous SO2 rich cloud was injected into the stratosphere, which will probably lead to global-scale cooling at the earth’s surface in the next few years, temporarily counteracting expected trends toward global warming ( Luo, 2002, vol.15, p.2806). “Mount Pinatubo also ejected .7-1.2 cubic miles of dacitic magma along with a large mass of gaseous sulfur” (Luhr, 1991, vol.354). The possibility that volcanic eruptions can modify the earth’s climate has been discussed for more than two centuries. Until about twenty years ago, it was believed that long-lived stratospheric clouds from volcanic eruptions consisted of fine ash or dust. “In the early 1970s, it was demonstrated that these stratospheric clouds actually consisted of micro-meter sized droplets of H2SO4, pointing to the important part played by sulfur in linking volcanoes to climate change” (Luhr, 1991, vol.354). The sulfur gases originally present in the magma are converted in the stratosphere to sulfuric acid aerosols. These gases cool the earth’s surface by back scattering and absorbing solar radiation. The stratospheric aerosol discharged from Mount Pinatubo’s eruptions, lead to the global scale cooling of 0.5 degrees Celsius in 1992-1993. Ultimately, the Pinatubo eruptions will provide an important test of global climate models (Luo, 2002, vol.15, p.2806). The quiet Pinatubo volcanic chain was adjacent to the Central Plain, which extends from the Lingayen Gulf to Mount Bataan on Manilla Bay. Mount Pinatubo was the highest volcano on this chain, rising 1745 meters above sea level before its 1991 eruption. Mount Pinatubo was one of the many volcanoes that made up the north – south Zambales Range. On April 2, 1991, the tranquility of the Zambales Range was broken when steam created a line of small explosion craters across the summit of the Pinatubo lava dome. The volcanic origin of the Zambales Range and the possibility of any sort of volcanic eruption had not been considered by the farmers of western Luzon or by the high tech aviators who flew in and out of Clark Air Base. Vol...