<P> Shocks of magnitude 3.2 or greater occurred at a slightly increasing rate during April and May with five earthquakes of magnitude 4 or above per day in early April, and eight per day the week before May 18 . Initially there was no direct sign of eruption, but small earthquake - induced avalanches of snow and ice were reported from aerial observations . </P> <P> At 12: 36 p.m. on March 27, phreatic eruptions (explosions of steam caused by magma suddenly heating groundwater) ejected and smashed rock from within the old summit crater, excavating a new crater 250 feet (75 m) wide and sending an ash column about 7,000 feet (2.1 km) into the air . By this date a 16,000 - foot - long (3.0 mi; 4.9 km) eastward - trending fracture system had also developed across the summit area . This was followed by more earthquake swarms and a series of steam explosions that sent ash 10,000 to 11,000 feet (3,000 to 3,400 m) above their vent . Most of this ash fell between 3 and 12 miles (5 and 19 km) from its vent, but some was carried 150 miles (240 km) south to Bend, Oregon, or 285 miles (460 km) east to Spokane, Washington . </P> <P> A second, new crater and a blue flame were observed on March 29 . The flame was visibly emitted from both craters and was probably created by burning gases . Static electricity generated from ash clouds rolling down the volcano sent out lightning bolts that were up to 2 miles (3 km) long . Ninety - three separate outbursts were reported on March 30, and increasingly strong harmonic tremors were first detected on April 1, alarming geologists and prompting Governor Dixy Lee Ray to declare a state of emergency on April 3 . Governor Ray issued an executive order on April 30 creating a "red zone" around the volcano; anyone caught in this zone without a pass faced a $500 fine or six months in jail . This precluded many cabin owners from visiting their property . </P> <P> By April 7, the combined crater was 1,700 by 1,200 feet (520 by 370 m) and 500 feet (150 m) deep . A USGS team determined in the last week of April that a 1.5 - mile - diameter (2.4 km) section of St. Helens' north face was displaced outward by at least 270 feet (82 m). For the rest of April and early May this bulge grew by 5 to 6 feet (1.5 to 1.8 m) per day, and by mid-May it extended more than 400 feet (120 m) north . As the bulge moved northward, the summit area behind it progressively sank, forming a complex, down - dropped block called a graben . Geologists announced on April 30 that sliding of the bulge area was the greatest immediate danger and that such a landslide might spark an eruption . These changes in the volcano's shape were related to the overall deformation that increased the volume of the volcano by 0.03 cubic miles (0.13 km) by mid-May . This volume increase presumably corresponded to the volume of magma that pushed into the volcano and deformed its surface . Because the intruded magma remained below ground and was not directly visible, it was called a cryptodome, in contrast to a true lava dome exposed at the surface . </P>

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