Transcript Some volcanic eruptions are quiet. The lava oozes down the side of

Shield Volcano
Shield volcanoes of Hawai'i are built of lava that erupts quietly, with
little explosion. Lava from shield volcanoes move rapidly for a long
distance before cooling. It is called a shield volcano because it has a
wide rounded top that resembles a warrior's shield laying flat on the
ground.
Mauna Loa
The Kilauea Iki eruption began on the morning of November 14,
1959, three months after a rapid increase in inflation of the ground
surface and the number and size of earthquakes. The eruption started
halfway up the 600-650 foo (180-200 m) south wall of the crater as a
curtain of fire a half-a-mile (0.8 km) long. Lava was ejected up to 100
feet (30 m) in the air. Photo courtesy of the U.S. Geological Survey.
Cinder Cone Volcano
Capulin Volcano in New Mexico
Wizard Island in the center of Crater
Lake in Oregon
Composite Volcano
Mount Shasta in California
Mount St Helens, a composite volcano
May 18, 1980
The May 18, 1980,
eruption sent an
ash plume over 15
miles into the
atmosphere.
Prevailing winds
carried the ash
plume to the
northeast, where it
turned daylight to
darkness over 120
miles away
beforePrior to the eruption high
mountain lakes like Obscurity Lake,
10 miles north of Mount St. Helens,
were characteristically clear due to
extremely low levels of dissolved
nutrients
afterThe same view after the
eruption shows the extent of
eruption damage to the forest
surrounding Obscurity Lake. Note
the large quantity of volcanic ash
that was eroded from adjacent
hillsides and deposited on large
deltas at the mouth of inlet
streams.
A pre-eruption view of
Mount St. Helens from
Spirit Lake shows the
smooth, conical slopes of
a very young, and
potentially explosive
volcano.
The same view shows the
profound change in the
volcano and Spirit Lake. The
formerly clear mountain lake
had been completely
displaced by the massive
landslide and choked with ash
and organic debris