Research about Kīlauea Caldera

USGS2021

Views of a century of activity at Kīlauea Caldera—A visual essay

The 2018 eruption of Kīlauea Volcano marked the end of the first sustained period of volcanic activity at Halemaʻumaʻu Crater in 94 years. The views of the lava lake (informally named “Overlook,” nestled within Halemaʻumaʻu) lasted for a decade and seemed timeless. But as we were recently reminded, the summit of Kīlauea is part of a dynamic system that has provided countless new views to observers over the centuries. This visual essay features a few of the many scenes recorded by early observers at the volcano, from the first visits by westerners in 1823 through the explosive eruption of 1924. The early images left by casual visitors, artists, and photographers raise many questions: What is shown? Where is this? Who captured the scene and when? How accurate is the portrayal? Where possible, we attempt to answer these questions and provide interpretations of the images featured. In 1912, the nature of observations at Kīlauea changed when Thomas A. Jaggar, Jr., and others occupied the Hawaiian Volcano Observatory on a full-time basis. They began a visual and written record of what they saw, heard, and experienced that has continued to this day. We describe some of the early work of these scientists and photographers, and showcase the results.

Hawaii↗

USGS2015

Reticulite‐producing fountains from ring fractures in Kīlauea Caldera ca. 1500 CE

A widely dispersed reticulite bed occurs close to the base of the Keanakākoʻi Tephra at Kīlauea Volcano. It can be divided into six subunits in the northern sector of the volcano; the reticulite also occurs in the southern sector, but outcrops are sparse owing to penecontemporaneous erosion and burial. Multilobate isopachs for each subunit and the total deposit suggest that multiple fountaining vents were distributed in the northern half of the caldera, possibly along ring fractures for the newly formed caldera. Isopach maps also show a sharp decline in thickness along the dispersal axis of each lobe, which could be explained by remobilization of tephra and/or inclined fountains. Despite such isopach characteristics, thinning rates calculated from the isopach data indicate that the fountains were among the most intense and powerful of all studied Kīlauea fountains. Density analyses of the pyroclasts suggest that fountaining was high (>600m) yet complex, possibly due to lava ponding and reentrainment. The calculated volume of the reticulite deposited around the caldera rim is approximately 0.2km 3 , more voluminous than the deposits of the 1959 Kīlauea Iki eruption; this volume is a minimum, however, as the low-density tephra is easily remobilized, and 600m high caldera walls probably trapped tephra within the caldera, which is deeply buried today and not accounted for in the volume calculations. The duration of this eruption was most likely at least a few days to weeks, based on the calculated volume and estimated discharge rates as seen during the Kīlauea Iki 1959 eruption.

Hawaii↗