Following the eruption Process_start of the Iran–Iraq War in September 1980 , an even greater effort was made by the Iranian government to crush Bodily_harm the Kurdish rebellion Violence , which was the only one of the 1979 uprisings Violence to still go on ( Arab , Baluchi , and Turkmen rebellions Violence had already been subdued Hindering by that time ) .

on may 18 , 1980 , a major volcanic eruption Catastrophe occurred Presence at mount st. helens , a volcano located in skamania county , in the u.s. state of washington .

The eruption ( a VEI 5 event ) was the most significant volcanic eruption Catastrophe to occur Presence in the contiguous 48 U.S. states since the much smaller 1915 eruption Catastrophe of Lassen Peak in California .

The eruption Catastrophe was preceded Process_start by a two-month series of earthquakes Catastrophe and steam-venting episodes , caused Causation by an injection Motion of magma at shallow depth below the volcano that created Creating a large bulge and a fracture system on the mountain 's north slope .

The eruption ( a VEI 5 event ) was the most significant volcanic eruption Catastrophe to occur Presence in the contiguous 48 U.S. states since the much smaller 1915 eruption Catastrophe of Lassen Peak in California .

An eruption Catastrophe column rose Motion_directional into the atmosphere and deposited Come_together ash in 11 U.S. states and significant ash in two Canadian provinces .

The eruption ( a VEI 5 event ) was the most significant volcanic eruption Catastrophe to occur Presence in the contiguous 48 U.S. states since the much smaller 1915 eruption Catastrophe of Lassen Peak in California .

It has often been declared Expressing_publicly the most disastrous volcanic eruption in U.S. history .

Thermal energy released during the eruption was equal to 26 megatons .

at the time of the eruption , the summit of the volcano was owned by the burlington northern railroad , but afterward the land passed to the united states forest service .

the aircraft flew Motion into a cloud of volcanic ash thrown up Motion by the eruption Catastrophe of mount unk ( approximately south-east of jakarta , indonesia ) , resulting in Causation the failure of all four engines .

The event is the namesake for the Vesuvian type of volcanic eruptions Catastrophe , characterized by eruption columns of hot gases and ash exploding into the stratosphere , although the event also included Cause_to_be_included pyroclastic flows associated Collaboration with Pelean eruptions Catastrophe .

The passage of Erika carried Carry_goods a cloud of volcanic ash to Antigua from the eruption of the Soufrière Hills Volcano on Montserrat , a rare occurrence .

The threat from the hurricane Catastrophe halted Process_end airplane evacuations Escaping on Montserrat , which was being threatened Warning by the eruption Process_start of the Soufrière Hills volcano .