Transcript Hawaii Hazard Map

Mahukona
Pacific Ocean
Kilauea Volcano and its Active Rift Zones, moving 2 cm/year
Mauna Loa
Kilauea
Halemaumau Caldera
motion of
south flank
fault
scarps
Mauna Loa Volcano
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Largest volcano on earth
has a caldera and two main rift zones
normal faulting, especially along southwest rift zone
giant submarine landslides off its southwestern flank
only has Subaerial Shield Stage rocks exposed
– all rocks are tholeiitic basalts
– Ninole Member, ~540 k.y.a.
• oldest exposed rocks on the island of Hawai‘i
• may represent an extinct earlier volcano or an early stage of Mauna Loa
• named for the Ninole Hills, former ridges between amphitheater-headed valleys
that have been overrun by later Mauna Loa eruptions
– Kahuku Member (unknown age)
• lavas that bury the Ninole Member
• separated from younger lavas by an erosional surface
– Ka‘u Member, 300 k.y.a. to present
• produced by current eruptive activity
• covers the surface of most of the volcano
– may be nearing the end of main shield-building activity since it has less
frequent eruptions than Kilauea
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Kilauea
Volcano
Most active volcano on earth
– has been continuously erupting since 1983 from vents on
the east rift zone
• has a caldera and two main rift zones
– caldera bounded by normal fault scarps
– faulting produces benches in the caldera walls
– rift zones have small lava shields, spatter cones, and
cinder cones
• slumping of southern (seaward) flank produces normal
faulting results from expansion of rift zones due to
dike injection seaward flank has dropped more than
600 meters
– Has caused large earthquakes and tsunamis
•only has Subaerial Shield Stage rocks exposed
–all rocks are tholeiitic basalts
–Hilina Member, 100 to 31 k.y.a
–Pahala Ash, ~31 k.y.a.
•contains Pele’s tears and Pele’s hair
–Puna Member, 30 k.y.a. to present
Continuous GPS Monitoring Records Magma Intrusion,
Kilauea Volcano, Hawai`i. Significant ground deformation
near the eruption site along part of the volcano's east rift zone
A sluggish black 'a'a lava flow from the Kilauea volcano advanced to about a quarter-mile of the
mostly vacant Royal Gardens subdivision in Lower Puna Jan 10, 2008.
Mauna Loa
Kilauea
Caldera
Mauna Loa
active
Shield Volcanoes of Hawaii
Mauna Kea
Dormant?
Lava
entry
in the
sea
Vog
Laze
Kilauea
Halemaumau
Caldera
Puu Oo
Magma
Chamber
Kilauea Shield Volcano
Volcanic Activity 1983-2007
1 Mauna Loa : The largest volcano on Earth measures almost 11 miles from the ocean floor. From sea level, its peak is
13,679 feet high.
2 Mauna Kea: The 13,796-foot peak houses some of the largest telescopes in the world.
3 Hawaiian Volcano Observatory
Built in 1986, the HVO replaced the original observatory which was built in 1912.
4 Kilauea Caldera
The large summit basin contains the smaller Halemaumau Crater. The caldera is 2 to 3 miles across and several hundred
feet deep.
5 Kilauea Iki : The collapsed cone along Kilauea's southwest rift zone means "Little Kilauea." The floor of the crater is
350 feet below its rim.
6 Puu Oo: The main eruptive vent in 1983-86 and 1992 to the present. It means "Hill of the Oo bird."
7 Magma reservoir: Believed to be located 1 to 4 miles beneath the surface.
8 Active conduit: Provides a passage for lava to vents on the rift zone.
9 Dormant conduit: A lava passageway that was once active.
10 Kupaianaha pond: The lava pond was the focus of the eruption in 1986-1992. Often translated as "mysterious," it can
also mean "amazing."
11 Steam plume\: Where lava is currently entering the ocean
12 Lava tube: A hollow passageway on the earth's surface created by the topmost layer of a lava flow solidifying while
the flow below remains liquid.
Kilauea’s Southwest Rift Zone
moving 2-3 cm/year
June 28, 2007: There is considerably less fuming at Pu'u 'O'o.
Sometimes this vent would emit more than 2,000 tons of sulfur
dioxide a day. Now it's emitting 200 tons a day. The significant
danger of this cinder and spatter cone lies in the instability of its
crater walls. The walls crack, crumble and are continuing to
collapse.
LAVA LAKE GROWING IN PU'U 'O'O: Lava continued to
flow yesterday inside Kilauea's Pu'u 'O'o crater. The U.S.
Geological Survey's Hawaiian Volcano Observatory reports
that the lava pond is steadily rising, fed by two active vents in
the crater 07/07/2007
Creation’s caldron : Kilauea's immense, enduring display expands the horizons of science
Glossary
Lava Bench / Lava delta >> An area of new rock at the edge of the sea, often several acres in
size, which rests on loose sand and rubble. Cone >> A pile of erupted material surrounding a
vent. Called puu in Hawaiian, which means any hill but usually a volcanic cone.
Dike >> A narrow, upright, underground wall of magma.
Flank >> The land area on one side or the other of a rift zone. On the Mauna Loa side of Kilauea,
Mauna Loa holds the land in place. On the seaward side, nothing holds the flank in place and it is
slipping into the sea.
Hornitos >> Hollow tubes of spattered lava, from a few inches to several yards high, which form
over lava tubes.
Intrusion >> Movement of magma into underground spaces without it bursting to the surface.
Laze >> "Lava haze," gases from lava hitting sea water, including steam and hydrochloric acid.
Littoral cone >> A cone at the edge of the sea formed by steam blasting lava in a spray, creating
a hill.
Rift zone >> Underground lines of broken rocks, marked by present and former eruptions, in
Kilauea's case extending on land 33 miles east and 19 miles southwest.
Shatter rings >> Surface areas above a lava tube where lava pressure has pushed the roof of a
tube up and down, breaking the ground in circles or ellipses as big as a football field.
Shield >> A round-topped volcano, one that looks like an open umbrella rather than a pointed
cone.
Tumulus >> A small, dome-shaped mound of lava.
Vent >> The small hole, often in a crater, where lava and gasses come from.
Vog >> "Volcanic smog," gases from an eruption, including sulfur dioxide, which can turn into
sulfuric acid causing Acid Rain.
A’a Lava is rough, chunky cinders
form a lava flow takes when it loses
heat and gas takes place rapidly.
Pahoehoe lava is smooth, fluid
form a lava flow takes when it
retains its heat and gas.
Types of lava
Lava tube
Lava can flow long distance
rapidly and with less friction
in a Lava Tube.
A lava tube is a hollow passageway on the earth's surface created by the topmost layer of a lava
flow solidifying while thehot molten flow below remains fluid..
`A`a just reaching one of the buildings at Kapoho School,
about 1000 January 28., 1960. The 1960 Kapoho Eruption of
Kilauea Volcano, Hawai`i.