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Negro, Cerro

Negro, Cerro

Vigorous strombolian eruptions from Nicaragua's Cerro Negro volcano in 1968 produce an ash-rich column above the vent. Strong incandescent lava fountaining can be seen at the base of the column. Steam rises from fumaroles on the righthand side of the cinder cone. Ash and cinders fall from the eruption column at the left.

Negro, Cerro

Negro, Cerro

A time exposure captures a nighttime view of a strombolian explosion in November 1968 from Cerro Negro volcano in Nicaragua. The trajectory of individual incandescent volcanic bombs can be seen radiating from the vent. Still-hot bombs continue to glow after landing on the outer flanks of the cinder cone. The 1968 eruption was one of many from Cerro Negro, Central America's youngest volcano.

Pacaya

Pacaya

Strombolian eruptions at Pacaya volcano in Guatemala produce a colorful nighttime display. This November 1988 time exposure traces the incandescent parabolic arcs of individual volcanic bombs explosively ejected from the vent. Larger bombs remain incandescent after they hit the surface of the cone and roll down its flank. The orange line at the lower right is a lava flow that issued from a fissure on the upper NW flank of MacKenney cone.

Paricutin

Paricutin

This spectacular nighttime time-exposure of Mexico's Paricutin volcano in 1948 shows strombolian ejection of incandescent blocks and their trails as they roll down the slopes of the cone. ParĂ­cutin is renowned as the volcano that was born in a cornfield in 1943. It grew to a height of more than 150 m within the first week of its appearance, and remained active until 1952.

Veniaminof

Veniaminof

Explosive eruptions eject fragmental material that drops from the eruption column, producing pyroclastic-fall deposits. The surface of the glacier in this 1983 photo of Alaska's Veniaminof volcano is darkened by ash. The grain size of the pyroclastic-fall fragments (collectively referred to as tephra) generally decreases away from the vent as larger and denser fragments fall first. The distribution of pyroclastic-fall deposits is influenced by wind direction. Eruptions much stronger than this one can distribute tephra hundreds of km or more from the volcano.

White Island

White Island

This 4-m-wide, water-filled impact crater was formed when the block in background, with volcanologist Ian Nairn providing scale, was ejected during a strombolian eruption from White Island in New Zealand in late March 1977. The block, composed of pre-existing wall rock of the crater, bounced, forming the impact crater, and then slid to its present location, 250 m from the source vent.


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