Historic flows of Mauna Loa. Thirty three in all (since 1843). 48% are summit eruptions (elevations greater than 12,000 ft). 6% are from radial vents (2 eruptions), northeast rift 24% and southwest rift zone 21%.
Compilation of all Mauna Loa flows to date. Over 500 flows have been mapped. The colors indicate age. The warmer the color the closer to present, the cooler the color the more old. Red flows are historic.
Northeast rift flows toward port of Hilo in foreground. Also reinforces the self righting mechanisms (orange-red flows).
3-D view of Southwest rift flows. The distance from rift to the sea is shorter on the west side than the east. Note the difference in slope between the east and west. West being steeper.
3-D view of Northwest flows. At the distal end near the coast is informally know as the Gold Coast. It has this name due to the high concentration of resort development in the area.
Historical activity in the region shown in red. Light gray lines represent outline of prehistoric lava flow contacts.
Talk Awareness of the most recent volcanic activity at Mauna Loa and Hualalai in Kona is very low. Only 22% of respondents were aware that Mauna Loa lava flows entered the ocean about 50 years ago. This figure shows the aerial distribution of lava flows erupted from Mauna Loa in 1950. These flows remain conspicuous in many places in South Kona.
Slope map and flow rates. Points: Warmer colors reflect steeper slopes Look at the flows on the south and southwest. Quite a few flows have entered the sea in less than one day once an eruption commenced. Flows on the northeast and northwest slopes encounter high slope initially and an intermontane region of shallow slopes. It is in this region that past eruptions have broken into several lobes which impede flow front progress. Essentially the flow fronts advance too slowly so that lava upstream jumps out of the current lava channel and begins to feed a secondary lobe. The net result is to divide the amount of lava into many lobes and thus the fronts slow and in some cases stagnate.
TALK 32% were aware that the last eruption of Hualalai was about 200 years ago. This figure shows the distribution of the c. 200 year old flows. We were surprised to find that a greater percentage of respondents were aware of the 200 year old lava flows than were aware of the 50 year old lava flows of Mauna Loa. Again, awareness was linked to proximity to the hazard source.
Size of Mauna Loa relative to Island of Hawai`i's other volcanoes.
OUTLINE OF Mauna Loa shown in Pink. General notes of shield volcano: Summit caldera is indicative of shallow magma storage.
Eruptive history of kilauea and mauna loa
Interpretation of Active Volcanoes Eruptive Histories of Kilauea, Mauna Loa, and Hualalai
Halema`uma`u 1902 The volcanoes have behaved very differently in the recent past!
Mauna Loa and Kilauea Both volcanoes appear to undergo long term cyclic behavior. Eruptive centers oscillate over centuries between the summit and rift zones.
<ul><li>1855-56 (threatened Hilo), </li></ul><ul><li>1859 (Village at Waianalii destroyed, ~12 mi S. of Kawaihae), </li></ul><ul><li>1859 (Village of “Kibele” (Kiholo) destroyed), </li></ul><ul><li>1868 (Kahuku, 37 buildings destroyed), </li></ul><ul><li>1880-81 (threatened Hilo, people fled town), </li></ul><ul><li>1916, 1919, 1926, S. Kona </li></ul><ul><li>1935, 42 (threatened Hilo), </li></ul><ul><li>1950, Pahoehoe in S. Kona </li></ul><ul><li>1984 (threatened Hilo, people evacuated?) </li></ul>Mauna Loa