H.I.Geocachers: Outside the Kipuka
Mauna Loa has erupted 33 times since 1843 (with other less well-dated eruptions going back to 1832 and before). These historical flows cover 806 km² of the volcano’s surface. Typically, these eruptions began in the summit caldera, Moku’aweoweo, with a curtain of fire (which is a 1 to 2 km line of lava fountains). Eruptions may consist solely of summit activity or they progress down- flank via rift zone dike propagation (in the subsurface) to feed flank vents. In the historic period, the Northeast Rift Zone has been the eruptive locus for 31% of the eruptions and covered 202 km² of land. The northwest quadrant has been the source of 6% of the eruptions (covering 130 km²), the Southwest Rift Zone has been the source for 25% of the eruptions (covering 233 km² of the land), and the summit region has been the site of 38% of the eruptions (many of the latter have remained in the summit caldera and thus covered little land, although others have spilled out into the northwest and northeast quadrants of the volcano).