By mid-afternoon, when these photos were taken, the drop in the lava lake level was obvious. A “bathtub ring” of black lava forming a rim on the vent wall (between the lighter-colored rocks higher in the wall and the surface of the lava lake) provides a record of the lake’s previous higher level. Photo taken Thursday, April 27, 2017 courtesy of USGS/HVO
Early this morning the lava lake level was measured at 12.5 m (41 ft) below the vent rim, the highest level the lake reached this month. But, at around 8:30 a.m., summit inflation switched to deflation and the lava lake level began to drop. Photo taken Thursday, April 27, 2017 courtesy of USGS/HVO
The episode 61g Kamokuna ocean entry has been slowly building a new lava delta for a little over a month now. Since our April 15 post, the delta has grown substantially. Two large cracks parallel to the coast are visible on the delta (center), with the distal portion slumping slightly seaward—suggesting further instability. Today, the ocean entry activity, most of which was located along the western side of the delta and obscured by the thick plume, was producing occasional weak littoral explosions. Photo taken Thursday, April 27, 2017 courtesy of USGS/HVO
On May 3, KÄ«lauea Volcano’s Kamokuna lava delta, which had been growing since late March, collapsed. An HVO time-lapse camera captured the sequence of events in five-minute intervals. This image shows the lava delta at 7:50 a.m. HST, a couple of hours before the collapse. Photo taken Wednesday, May 3, 2017 courtesy of USGS/HVO
Between 9:35 and 9:40 a.m., a large steam plume appeared in the middle of Kamokuna lava delta in the area of large cracks noted in our April 27 image (see below). Weak fountaining or spattering likely occurred initially, because new tephra is visible in the steaming area, but that activity ended by 9:40 a.m. Images captured over the next 25 minutes show that the steam plume in the middle of the delta weakened, and the delta surface surrounding the steaming area subsided. Photo taken Wednesday, May 3, 2017 courtesy of USGS/HVO
Within five minutes, between 9:55 and 10:00 a.m. HST, nearly the entire delta disappeared, collapsing into the sea. The collapsed area cut back toward the sea cliff, past the largest crack on the delta. In this image, captured at 10:05 a.m., the seawater is brown and turbulent. Large blocks of steaming rocks are visible on top of a narrow slice of the remaining delta (center). These rocks were likely washed ashore by a small, localized tsunami generated by the collapse. During the next few hours, small pieces of the remnant delta continued to flake off and disappear into the ocean. Photo taken Wednesday, May 3, 2017 courtesy of USGS/HVO
This morning (May 4), the Kamokuna ocean entry was obscured by a thick steam plume at the base of the cliff. Sparse littoral bursts, occasionally visible through the plume, were the source of the floating, steaming lava fragments that can be seen in the ocean near the entry. Photo taken Wednesday, May 3, 2017 courtesy of USGS/HVO
Time-lapse thermal image movie of Halemaumau Overlook Vent. April 27-May 4, 2017. Images courtesy of USGS/HVO
Time-lapse movie of Halemaumau Overlook Vent. April 27-May 4, 2017. Images courtesy of USGS/HVO
Time-lapse movie of Halemaʻumaʻu Overlook Vent from Hawaiian Volcano Observatory. April 27-May 4, 2017. Images courtesy of USGS/HVO
Time-lapse movie of KÄ«lauea Caldera from Hawaiian Volcano Observatory. April 27-May 4, 2017. Images courtesy of USGS/HVO
Time-lapse movie of Halemaumau Crater looking Southwest. April 27-May 4, 2017. Images courtesy of Hawaii Volcanoes National Park
(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)
This past week, KÄ«lauea Volcano’s summit lava lake level fluctuated in concert with summit inflation and deflation, ranging 15-32 m (49-105 ft) below the vent rim. On the East Rift Zone, the 61g flow was still active, with lava entering the ocean near Kamokuna and surface breakouts downslope of Pu‘u ‘Ō‘Å. These flows do not pose an immediate threat to nearby communities. On May 3, the front section of the Kamokuna lava delta collapsed into the sea, a reminder that new land created by ocean entries is highly unstable and prone to collapse without warning.
Mauna Loa is not erupting. During the past week, small-magnitude earthquakes were recorded primarily beneath the upper Southwest Rift Zone at depths up to 5 km (3 mi), and the upper west flank at depths of about 7-8 km (4-5 mi). A magnitude-3.1 earthquake occurred in the upper Southwest Rift Zone on April 28. GPS measurements continue to show deformation related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone. No significant changes in volcanic gas emissions were measured.
One earthquake was reported felt on the Island of Hawaiʻi during the past week. On May 3, at 1:32 p.m. HST, a magnitude-3.2 earthquake occurred in 2.9 km (1.8 mi) south of Kīlauea’s summit at 2.8 km (1.7 mi) depth.
Please visit the HVO website (http://hvo.wr.usgs.gov) for past Volcano Watch articles, KÄ«lauea daily eruption updates, Mauna Loa weekly updates, volcano photos, recent earthquakes info, and more; call for summary updates at 808-967-8862 (KÄ«lauea) or 808-967-8866 (Mauna Loa); email questions to askHVO@usgs.gov.
Time-lapse movie of Pu’u ‘O’o Crater. April 27-May 4, 2017. Images courtesy of USGS/HVO
Time-lapse image movie from a research camera positioned on Holei Pali, looking east towards Lava Flow 61G and Kalapana. April 27-May 4, 2017. Images courtesy of USGS/HVO
This map shows recent changes to Kīlauea’s East Rift Zone lava flow field. The area of the active flow field as of April 10 is shown in pink, while widening and advancement of the active flow as of May 3 is shown in red. Older Puʻu ʻŌʻŠlava flows (1983–2016) are shown in gray. The yellow line is the trace of the active lava tube (dashed where uncertain).
The blue lines over the PuÊ»u ʻŌʻŠflow field are steepest-descent paths calculated from a 2013 digital elevation model (DEM), while the blue lines on the rest of the map are steepest-descent paths calculated from a 1983 DEM (for calculation details, see http://pubs.usgs.gov/of/2007/1264/). Steepest-descent path analysis is based on the assumption that the DEM perfectly represents the earth’s surface. DEMs, however, are not perfect, so the blue lines on this map can be used to infer only approximate flow paths. The base map is a partly transparent 1:24,000-scale USGS digital topographic map draped over the 1983 10-m digital elevation model (DEM).
This small-scale map shows Kīlauea’s active East Rift Zone lava flow field in relation to the southeastern part of the Island of Hawaiʻi. The area of the active flow field as of April 10 is shown in pink, while widening and advancement of the active flow as of May 3 is shown in red. Older Puʻu ʻŌʻŠlava flows (1983–2016) are shown in gray.
The blue lines over the PuÊ»u ʻŌʻŠflow field are steepest-descent paths calculated from a 2013 digital elevation model (DEM), while the blue lines on the rest of the map are steepest-descent paths calculated from a 1983 DEM (for calculation details, see http://pubs.usgs.gov/of/2007/1264/). Steepest-descent path analysis is based on the assumption that the DEM perfectly represents the earth’s surface. DEMs, however, are not perfect, so the blue lines on this map can be used to infer only approximate flow paths. The base map is a partly transparent 1:24,000-scale USGS digital topographic map draped over the 1983 10-m digital elevation model (DEM).
Like this:
Like Loading...
Leave a Reply