VOLCANIC LANDFORMS OF HAWAII VOLCANOES NATIONAL PARK
VOLCANIC LANDFORMS OF HAWAII VOLCANOES NATIONAL PARK
Halemaumau, a pit crater, is a well known feature in Hawaii Volcanoes
National Park. The floor of Kilauea Caldera surrounds Halemaumau. The
caldera wall is in the distance. Photo by Dorian Weisel, U.S. Geological
Survey, June 3, 1990.
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Background:
There are a large numbers of volcanic landforms in the national park
that are common on shield volcanoes and on volcanic landscapes made of
basaltic lava. Fortunately, most of these landforms are easily
recognizable and have descriptive names. The best way to learn these
features is to use the photographs and list of definitions below. The
photos are supplemented with figures and maps.
A caldera is a "large, basin-shaped volcanic depression, more or
less circular ... the diameter of which is many times greater than that
of the included vent or vents" (Bates and Jackson, 1980). Kilauea
caldera is at the summit of Kilauea Volcano and has a diameter of 2 by 3
miles (4.5 km by 3 km). The caldera has been slowly filling by episodic
eruptions since 1790.
Aerial view of the summit of Kilauea Volcano. Halemaumau Crater, near
the center of the photo, is the main vent inside Kilauea Caldera and is
0.6 miles (1 km) in diameter. The light-colored areas near the crater
are mineral deposits that precipitated from gases. The dark lava flow to
the east (just below) of the crater erupted in 1982. The road around the
perimeter of the caldera is
Crater Rim Drive.
Jaggar Museum and the Hawaiian Volcano Observatory are located on
Uwekahuna bluff, 470 feet (145 m) above the caldera floor, and can be
seen in the upper right of the slide.
Kilauea Iki Crater
is on the bottom near the center. The buildings near the north rim of
the caldera (right margin of the photo) are Kilauea Visitor Center (Park
Headquarters) and the Volcano House Hotel. Volcano Village is at the
bottom right corner of the photo. Note the change from forest to
desert. Photograph by J.D. Griggs, U.S. Geological Survey, January 10, 1985.
Mokuaweoweo caldera is at the summit of Mauna Loa Volcano. The
caldera is 2.7 miles long by 1.6 miles wide (4.3 by 2.5 km). This photo
is a view across Mokuaweoweo Caldera looking to the north. Immediately
north and south of the caldera are pit craters, appropriately named North
Pit and South Pit. Photograph by Jack Lockwood, U.S. Geological Survey,
December 1, 1981.
Mokuaweoweo Caldera can also be seen from space. The Island of
Hawaii
is made up of five volcanoes:
Kohala,
Mauna Kea,
Hualalai,
Mauna Loa,
and
Kilauea.
This space
shuttle photograph shows the characteristic features of each volcano. On
the north flank of Kohala Volcano, just to the west (right) of the
clouds, lies deeply eroded Pololu Valley. Light colored glacial deposits
cap the summit of Mauna Kea Volcano. The 1800-1801 lava flows are
clearly visible on the northeast rift of Hualalai Volcano. Historical
lava flows drape the northeast and southwest rift zones of Mauna Loa
Volcano. Most of Kilauea Volcano is obscured by clouds, except for the
southwest rift zone. Courtesy of NASA and the
Hawaii Space Grant College,
University of Hawaii.
This color infrared space shuttle photograph shows Mauna Loa and Kilauea
Volcanoes. Mauna Loa's Mokuaweoweo Caldera is to the left of center.
The northeast and southwest rift zones are the source of the historical
lava flows. Hilo Bay is at the top right. The summit of Kilauea is
obscured by clouds. Historical lava flows of its southwest rift zone are
just below the center. Aa lava flows from the early episodes of the Puu
Oo eruption are visible near the right center. Notice the small plume
from the on-going eruption. Courtesy of NASA and the Hawaii Space Grant
College, University of Hawaii.
A pit crater is a "crater formed by the sinking in of the surface;
not primarily a vent for lava" (Macdonald and Abbott, 1977, p. 419). The
upper segment of the east rift zone of Kilauea Volcano is defined by
several pit craters. Most of these pit craters can be seen along the
Chain of Craters Road.
Makaopuhi
Crater, shown in this photo, is 1 mile by 0.6 mile (1.5 km by 1 km) and
is about 500 feet (150 m) deep. Lava flows from the Mauna Ulu eruption
(1969-1974) are at the upper right. This pit crater is estimated to be
500 years old (J.P. Lockwood, personal communication, 1979, in Hazlett,
1990). Photograph by J.D. Griggs, U.S. Geological Survey, January 10, 1985.
In Hawaii, a rift zone is a "zone of volcanic features associated
with underlying dike complexes" (Bates and Jackson, 1980, p. 538). Magma
leaves a storage area beneath the summit of the volcano and intrudes the
rift zone at a depth of 0.6-3 miles (1 to 5 km). The intrusions are
vertical and tabular, typically 5-10 feet (2-3 m) in width and 1.2 miles
(2 km) in height. These planar, tabular-shaped intrusions of liquid
magma are called dikes. They are also called dikes after the magma
solidifies. The intrusion of magma causes the volcano to grow
laterally. Intrusions can also cause cracking at the surface. This
photograph is an aerial view of the southwest rift zone of Kilauea
Volcano. The view is to the northeast. Crater Rim Drive is near the top
of the slide. The darker lava flows are from the September 1971
eruption. The brown tephra seen within the cracks is from the explosive
eruption of 1790. The cracks develop as magma passes beneath the
surface, causing the surface to extend. Photograph by J.D. Griggs, U.S.
Geological Survey, March 4, 1985.
A cinder cone is a "conical hill formed by the accumulation of
cinders and other pyroclasts, normally of basaltic and andesitic
composition" (Bates and Jackson, 1980, p. 112). Cinders are a type of
pyroclastic
material. Puu Puai, shown in this photo,
is a cinder cone that formed during the 1959 eruption at
Kilauea Iki Crater.
Gas leaving the magma propelled incandescent cinder and ash as high as
1,900 feet (580 m) above the vent. Tradewinds blew the tephra to the
southwest, where it accumulated to form the cinder cone. Puu Puai is
visible from Crater Rim Drive and from Devastation Trail. Photograph by
T.J. Takahashi, U.S. Geological Survey, September 22, 1984.
Puu Oo is a cinder and spatter cone created by fountaining eruptions from
1983-1986. Cinder can be seen falling from a Puu Oo lava fountain in
this photo. Photograph by J.D. Griggs, U.S. Geological Survey, June 30,
1984.
A spatter cone is a "low, steep-sided cone of spatter built up on a
fissure or vent; it is usually of basaltic material" (Bates and Jackson,
1980, p. 598). Spatter is globs of lava thrown through the air. The
spatter cone in this photo formed during the April 30, 1982, eruption
near Halemaumau Crater. Numerous spatter cones formed along a 0.3 mile
(0.5 km) fissure that was active for 20 hours. These spatter cones can
be visited by walking beyond the Halemaumau Crater overlook to the
intersection of
Halemaumau and Byron's Ledge trails
. Photograph by T.T. English, U.S. Geological Survey, April 30, 1982.
A spatter rampart is a " ridge of congealed pyroclastic material,
usually basaltic, built up on a fissure or vent" (Takahashi and Griggs,
1987). Pyroclastic refers to fragmented volcanic material ejected from a
volcano. A vent is an opening at the Earth's surface through which
volcanic material is extruded. The spatter rampart shown in this photo
was the principal vent of the 1984 eruption on the northeast rift zone of
Mauna Loa Volcano. Photograph by J.D. Griggs, U.S. Geological Survey,
March 26, 1984.
A littoral cone is a "cone formed on a lava flow when it runs into a
body of water, usually the sea. Such cones are the result of steam
explosions that hurl into the air large amounts of ash,
lapilli,
and small
bombs
derived from the new lava"
(Bates and Jackson, 1980, p. 365). During the
Kupaianaha eruption,
lava tubes advanced to the
coastal area of the park and dumped lava into the ocean. The resulting
steam explosions generated
spatter rampart,
limu o Pele,
and
Pele's hair
that accumulated on the
sea cliff to make a littoral cone. This photo shows a littoral cone
that formed in October 1988. Lava from the tube added new land,
extending the coastline and isolating the littoral cone. Subsequent
slumping of the new land produced the low fault scarp in front of the
cone. Fresh lava flows covered the down-dropped area. The yellow areas
near the cone are covered by sulfur that precipitated from volcanic
gases. Photograph by J.D. Griggs, U.S. Geological Survey, October 5, 1988.
A perched lava pond is an "impounded body of pahoehoe lava whose
margins consist of chilled lava-flow fronts or spatter ramparts formed
earlier in the same or previous eruption. The surface of the pond is
thus retained at a higher (perched) level one or more meters above the
surrounding surface" (Takahashi and Griggs, 1987). This photo shows a
lava pond on the north flank of the Mauna Ulu satellite shield on the
upper east rift zone of Kilauea Volcano. The diameter of the pond is 425
ft (130 m). Park visitors can see this perched lava pond by walking one
mile (1.6 km) on the
Napau Crater trail
and climbing Puu Huluhulu, a prehistoric cinder cone. Photo
by Steve Mattox, 1995.
A lava tube is a "hollow space beneath the surface of a solidified
lava flow, formed by the withdrawal of molten lava after the formation of
the surficial crust" (Bates and Jackson, 1980, p. 353). Nahuku
(Thurston) lava tube is on Crater Rim Drive and visited by millions of
park visitors every year. The lava tube is up to 13 ft (4 m) in height
and about one mile in length. The lava tube developed about 400 years
ago and carried lava away from a vent near the present location of
Kilauea Iki Crater. Photograph by T.J. Takahashi, U.S. Geological
Survey, September 7, 1984.
A tumulus is a "doming or small mound on the crust of a lava flow,
caused by pressure due to the difference in rate of flow between cooler
crust and more fluid lava below. Unlike a lava blister ... it is a solid
structure" (Bates and Jackson, 1980, p. 669). The tumulus shown in this
photo is on the south flank of Kilauea Volcano. Photograph by
Janet Babb, June, 1990. Used
with permission.
A fissure is a "surface of fracture or a crack in rock along which
there is a distinct separation" (Bates and Jackson, 1980). A fissure
eruption is an "eruption that takes place from an elongate fissure rather
from a central vent" (Bates and Jackson, 1980).
The fissure in this photograph was a vent for an early episode of the Puu
Oo eruption. Lava trees are prominent on the horizon. Spatter covers
the ground adjacent to the fissure. Lava within the fissure is red, due
to oxidation. Photograph by C. Neal, June 25, 1983, U.S. Geological Survey.
A fault is a surface along which rocks slide past one another. A
fault scarp is a "steep-slope or cliff formed directly by movement along
a fault and representing the exposed surface of the fault before
modification by erosion and weathering" (Bates and Jackson, 1980, p.
224). The motion of faults is described in a relative sense. The
hanging wall is the "overlying side of an orebody, fault, or mine
working; esp. the wall rock above an inclined vein or fault" (Bates and
Jackson, 1980, p. 283). The footwall is the "underlying side of a fault
... esp. the wall rock beneath an inclined fault" (Bates and Jackson,
1980, p. 241).
For most of the surface faults on Kilauea, the hanging wall has moved
down relative to the footwall to produce a normal fault. Normal faults
are common in areas that are undergoing extension. The fault scarps of
the Hilina fault system are the major landforms in the coastal area of
the park. These fault scarps are as high as 1,600 feet (490 m),
resulting of seaward movement of unsupported rocks over thousands of
years. Halape is on the coast along the right margin of the photo.
Photograph by D.A. Swanson, June 24, 1971, U.S. Geological Survey.
Click here for a list of
activities and teaching suggestions about volcanic landforms of Hawaii
Click here for a list of
references about the volcanic landforms.
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