An earthquake swarm occurred at Loihi during 10-11 September and two 13 September earthquakes may have also been part of the swarm. The two later earthquakes occurred at 0311 and 0839 and had magnitudes of 4.9 and 4.4, respectively. Most of the earthquakes from 10-13 September were ~12 km deep and located slightly S of the summit of the volcano.

12 September 2001            Back to Top

An earthquake swarm occurred at Loihi during 10-11 September and two 13 September earthquakes may have also been part of the swarm. The two later earthquakes occurred at 0311 and 0839 and had magnitudes of 4.9 and 4.4, respectively. Most of the earthquakes from 10-13 September were ~12 km deep and located slightly S of the summit of the volcano.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO)

5 September 2001            Back to Top

On 10 September an earthquake swarm began at Loihi. The swarm began with a M 5 earthquake and was followed by M 3.5-4.5 earthquakes until at least 11 September. This was the most severe swarm at Loihi since July 1996, when the summit collapsed.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO)

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Clague D A, Davis A S, Bischoff J L, Dixon J E, Geyer R, 2000. Lava bubble-wall fragments formed by submarine hydrovolcanic explosions on Loi'hi Seamount and Kilauea volcano. {Bull Volc}, 61: 437-449

Fornari D J, Garcia M O, Tyce R C, Gallo D G, 1988. Morphology and structure of Loihi seamount based on SEABEAM sonar mapping. {J Geophys Res}, 93: 15,227-15,238

Garcia M O, Rubin K H, Norman M D, Rhodes J M, Graham D W, Muenow D W, Spencer K, 1998. Petrology and geochronology of basalt breccia from the 1996 earthquake swarm of Loihi seamount, Hawaii: magmatic history of its 1996 eruption. {Bull Volc}, 59: 577-592

Guillou H, Garcia M O, Turpin L, 1997. Unspiked K-Ar dating of young volcanic rocks from Loihi and Pitcairn hot spot seamounts. {J Volc Geotherm Res}, 78: 239-249

Klein F W, 1982. Earthquakes at Loihi submarine volcano and the Hawaiian hot spot. {J Geophys Res}, 87: 7719-7726

Klein F W, Koyanagi R Y, 1979. Seismicity of Kilauea and Loihi volcanoes, Hawaii (abs). {Hawaii Symp Intraplate Volc & Submarine Volc, Hilo, Hawaii, Abs}, p 124

Malahoff A, 1987. Geology of the summit of Loihi submarine volcano. {U S Geol Surv Prof Pap}, 1350: 133-144

Moore J G, Clague D A, Normark W R, 1982. Diverse basalt types from Loihi seamount, Hawaii. {Geology}, 10: 88-92

Moore J G, Normark W R, Lipman P W, 1979. Loihi seamount-a young submarine Hawaiian volcano (abs). {Hawaii Symp Intraplate Volc & Submarine Volc, Hilo, Hawaii, Abs}, p 127

Robinson J E, Eakins B W, 2006. Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge. {J Volc Geotherm Res}, 151: 309-317

Loihi seamount, the youngest volcano of the Hawaiian chain, lies about 35 km off the SE coast of the island of Hawaii. Loihi (which is the Hawaiian word for "long") has an elongated morphology dominated by two curving rift zones extending north and south of the summit. The summit region contains a caldera about 3 x 4 km wide and is dotted with numerous lava cones, the highest of which is about 975 m below the sea surface. The summit platform includes two well-defined pit craters, sediment-free glassy lava, and low-temperature hydrothermal venting. An arcuate chain of small cones on the western edge of the summit extends north and south of the pit craters and merges into the crests of Loihi's prominent rift zones. Deep and shallow seismicity indicate a magmatic plumbing system distinct from that of Kilauea volcano. During 1996, a new pit crater was formed at the summit of the volcano, and lava flows were erupted. Continued volcanism is expected to eventually build a new island at Loihi; time estimates for the summit to reach the sea surface range from roughly 10,000 to 100,000 years.