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Copy of Copy of Volcano template
Transcript of Copy of Copy of Volcano template
Impact of Last Eruption
Pictures of Mauna Loa's last eruption (1984)
about Last Eruption
Mauna Loa 1942
Tectonic Plates and
3D illustration of the Hawaiian chain of islands
Mauna Loa is the Hawaiian name for “Long mountain”
This "long mountain" about 120km from the southern tip of the island to the summit and then North-East to the coastline near Hilo.
Mauna Loa is a shield volcano
Composed almost entirely of hardened basaltic lava flows
Among Earth's most active volcanoes.
Mauna Loa is one of the five volcanoes that form the Island of Hawaii
Mauna Loa is one of the largest volcanoes on earth in terms of volume and area covered.
Cover at least half of the Island of Hawaii.
Mauna Loa by itself cover about 85% of all the other Hawaiian Island combined.
Lava eruptions at Mauna Loa are silica-poor and very fluid.
Eruptions are generally non-explosive
The Volcano has shallow slopes.
Occurs in the specific ocean and is part of the U.S state of Hawaii.
Location: 19.475N 155.608 W
Elev. Above Sea Level: 4,170 m
Elev. Below Sea Level: about 5000m
Area: 5,271 km2 (50.5% of Hawaii)
about 300km deep
Volume: 80,000 km3
About Mauna Loa
Most Recent Eruption:
March 24 & April 15, 1984
Number of Historical Eruptions:
33 eruptions since 1843
Oldest Dated Rocks:
Between 100,000 and 200,000 years ago
Estimated Age of Earliest Sub-aerial Eruption: About 400,000 years ago
Estimated Age of First Eruption: Between 1,000,000 and 700,000 years ago
Hawaiian Volcano Stage: Shield-forming stage
The primary hazardous effect:
unrestrained high-volume lava flows.
The walls of burning rock envelop and destroy anything in their way.
The flows can burn houses down and cover the ground with a thick impenetrable layer of black rock.
About 42 km2 of land were paved over by the 1984 flows.
The fluid, high-velocity flows of 1984 stopped just 6.5km short of the coastal town of Hilo as residents packed to evacuate
Other effects of the 1984 eruption
Aside from flood basalts, Mauna Loa's caldera emitted a noxious mixture of fumes called volcanic smog (or "vog").
This smelly gas is a combination of sulfur dioxide, carbon dioxide and hydrogen sulfide.
The smog reacts with atmospheric moisture, sunlight and oxygen to form acidic aerosols that contributed to the creation of acute acid rainfall.
The aerosol pollutants caused probable lung degradation and threatened respiratory function, especially in children and asthmatics.
The magma comes from the Hawaii hotspot
This lead to the creation of the Hawaiin island chain over tens of millions of years.
The slow drift of the Pacific Plate will eventually carry Mauna Loa away from the hotspot
May occur within 500,000 to one million years from now thus becoming extinct
Eruption history of Mauna Loa
The 1984 Mauna Loa eruption continued for 3 weeks and began around 1:30 a.m on March 25.
It started in the southwest corner of the volcano's Moku'aweoweo summit crater.
Within three hours, 80% of the crater was covered with lava, but it never breached the rim.
The eruption then shifted to the opposite side of the caldera.
Other high-volume basalt floods flowed out of rift zones on Mauna Loa's flanks.
The eruption triggered landslides of basaltic rock on the volcanic mountain's shoulders and slopes.
Most recent eruption
Fun Facts About Volcanoes:
The loudest noise ever known was produced by a volcanic eruption at Krakatoa, near Javan, in 1883. The sound was heard in Australia, 5000 km away.
When Laki volcano in Iceland erupted in 1783, its lava flow stretched 65 km, the longest ever recorded.
There are over 500 active volcanoes in the world.
About 20 per cent of all volcanoes are underwater.
About 20 to 30 volcanoes erupt each year, mostly under the sea. ava from an erupting volcano may be as hot as 1200 degrees centigrade.