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June 24, 2004

A weekly feature provided by scientists at the Hawaiian Volcano Observatory.

"Remember the Maine," a lost horse, and Mount Pinatubo

History is sometimes altered by events so insignificant that they pass without notice when they occur. Let's follow the chain of events that placed an American air base in the Philippines, in the shadow of Mount Pinatubo-a volcano whose eruptions devastated the base in 1991.

By the end of the nineteenth century, the once great Spanish colonial empire was disintegrating. One remaining colony was Cuba, where American businessmen had large investments in the thriving sugar industry. Spanish repression of a Cuban independence movement threatened the sugar industry and produced wholesale human-rights abuses.

President McKinley was under tremendous public pressure to defend U.S. interests on the island. Newspaper chains owned by William Randolph Hearst and Joseph Pulitzer whipped up much of the American outrage against the Spanish colonial government. In February 1898, the American battleship U.S.S. Maine exploded and sank in Havana harbor. Americans blamed the Spanish, though there was no good evidence of Spanish involvement. The lust for war escalated. In late April, at McKinley's request, Congress proclaimed Cuban independence-effectively a declaration of war.

The first hostile action took place in the Philippines, in Manila Bay, on the first of May. An American fleet destroyed all Spanish ships in the Bay. The Spanish-American war didn't last long. A treaty was signed on December 10 that granted Cuba its independence and ceded the Philippines, Guam, and Puerto Rico to the U.S. in exchange for 20 million dollars.

The defeat of Spain didn't bring peace to the Philippines-not for long, anyway. Filipino Nationalists declared independence in January 1899, and Filipino-American hostilities began a short time later.

Numerous battles were fought in and around the town of Angeles in Luzon. The last took place on November 5, 1899, when American cavalry executed a decisive flanking movement. The American units were commanded by Major General Arthur MacArthur-father of Douglas MacArthur.

The horses in the cavalry units didn't fare well on the abundant "sawgrass" near the American bivouac sites. In fact, they sickened and eventually died if they ate enough of it. So hay was brought by ship from the mainland-expensive and time-consuming. Legend has it that one day a missing horse-probably tired of the same old grinds-was found grazing in a field near Angeles. The horse didn't get sick from the grass he ate during his adventure, so other horses were allowed to graze in the same field. They, too, suffered no ill effects, so the bivouac was moved to the site with the good grass. In 1902 a large military reservation called Fort Stotsenberg was established around the former bivouac.

Aviation came to Fort Stotsenberg in 1912, when a single aircraft was stationed there. In 1919, a small runway was built and named Clark Field. Fort Stotsenberg and Clark Field were controlled by the Japanese during the Second World War. American forces led by General Douglas MacArthur regained control in January 1945. The Philippines received independence in 1946, but a series of Filipino-American agreements permitted the U.S. to remain at Stotsenberg and other military bases. In 1949 the entire facility was renamed Clark Air Base.

All this time, few realized that Mount Pinatubo-the craggy peak on the western skyline-was a volcano, and that Clark Air Base was built on deposits erupted from it. In fact, those deposits were probably responsible for the growth of horse-friendly grass. Pinatubo's identity as a volcano became known to the entire world on June 15, 1991, when, after escalating unrest and lesser eruptions, it produced the second largest eruption of the twentieth century.

The eruption devastated Clark Air Base and adjacent communities and damaged the U.S. Navy base and communities at Subic Bay south of the volcano. This occurred while the lease agreement permitting the U.S. to use the bases was under renegotiation. Many Filipinos wanted the bases returned, because they represented the last vestiges of colonialism. This drove up the price demanded to renew the lease. But the U.S. facilities near Mount Pinatubo were damaged goods. They would be expensive to repair, and Pinatubo might very well erupt again. So, the lease was not renewed, the Air Force transferred Clark Air Base to the Philippines in November 1991, and the Navy withdrew from Subic Bay in October 1992.

Activity update

Eruptive activity at Pu`u `O`o continues. The Banana flow, which breaks out of the Mother's Day lava tube a short distance above Pulama pali, is entering the ocean in two areas off the 2002 Wilipe`a lava delta. The national park has marked a trail to within a short distance of the active lava deltas, and thousands have been enjoying the show. In addition, lava has been visible between Pulama pali and Paliuli for the past two weeks. Eruptive activity in Pu`u `O`o's crater is weak, with sporadic minor spattering and small flows.

No earthquakes were reported felt on the island during the week ending June 23.

Mauna Loa is not erupting. The summit region continues to inflate slowly. Seismic activity remains low, with only 3 earthquakes located in the summit area during the past week.

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Updated: July 15, 2004 (pnf)