Images

An Unmanned Aircraft Systems overflight on Sunday afternoon (Sept. 2, 2018) showed that lava remained active within the fissure 8 cone.

This UAS oblique image of fissure 8 shows that the new lava is mostly confined to the crater floor within the cone, although a small amount extended a short distance into the spillway. HVO geologists noted that the lava activity was at a low level, with the area of incandescence decreasing to almost zero over the course of the afternoon.

Early this morning, the Unmanned Aircraft Systems team was able to conduct a brief overflight of fissure 8 between passing rain showers, which resulted in abundant steaming on the flow field.

Geologic field-trip guide of volcaniclastic sediments from snow- and ice-capped volcanoes—Mount St. Helens, Washington, and Mount Hood, Oregon: U.S. Geological Survey Scientific Investigations Report 2017–5022–F, 97 p., https://doi.org/10.3133/sir20175022F.

Another aerial view of the summit crater from this morning's overflight. Zoom in to see HVO and the Park's Jaggar Museum on the caldera rim (right side of photo).

This view across the summit caldera shows ground cracks (center) just north of Halema‘uma‘u. Rockfalls within the crater and along the caldera walls continue to stir up dust that can be seen here rising above the caldera rim.

An Unmanned Aircraft Systems overflight of fissure 8 on August 21, 2018, showed no incandescence within the cinder cone. Minor amounts of gases, primarily steam, rose from the north wall of the cinder cone and from areas along the lower East Rift Zone. The interior walls of the fissure 8 cone and lava channel are slumping downward and inward.

HVO field crews carefully traverse the uneven surface of the channel levee (left of image) to make measurements of the fissure 8 lava channel. The lava is slowly cooling and contracting but the area remains warm (note the steam rising). The view is to the east, with Puu Honuaula in the distance (right of image).

Void spaces within the cooled lava channel and along the channel margins create hazardous conditions on the fissure 8 flow field. Here, part of the void is visible, but a fragile veneer of lava hides other parts of it (upper right).

The south edge of the lava flow showed no incandescence this morning and remained less than 0.1 miles from the Pohoiki boat ramp in Isaac Hale Park. The main ocean entry area was still in the Ahalanui area.

The caldera floor near Halema‘uma‘u is a jumble of down-dropped blocks and surface cracks. HVO field crews hiked along the roadway to verify the location of benchmarks (lower left) and prepare for additional geophysical work to document the changes. The road provided access to the Overlook parking area, closed since 2008.

Nighttime view of fissure 8 lava as it exits the vent and feeds into the channel.

View from the bank of the cooling lava channel near the Leilani Estates subdivision. The height difference between the channel (right) and upper bank (left) is about 8 m (26 ft). Although lava is not flowing from fissure 8, the lava flow field includes large areas of still-hot, rugged, and unstable lava surfaces.

This morning, USGS scientists flying over fissure 8 noticed a change in the vent from yesterday. Gas jets were throwing spatter—fragments of glassy lava (light gray deposits)—from small incandescent areas deep within the cone. This activity is an indication that the lower East Rift Zone eruption may be paused rather than pau (over).

Data from continuous GPS stations indicate how the ground is moving over time. Station WLWY, near White Lake on the Sour Creek resurgent dome in Yellowstone caldera, has been operating since 2001. This plot shows vertical ground motion recorded at the site.

Temperature record from Echinus geyser outflow channel for October 17–20, 2017. The plot captures a time when the geyser went from occasional eruptions to semi-regular eruptions (signified by temperature spikes after about 12:00 on October 18) occurring about every 2 hours.

View from this morning's helicopter overflight of the Pohoiki boat ramp at Isaac Hale Park shows black sand, transported to the southwest by longshore currents, blocking the entrance to the small boat harbor.

Lava continues to ooze into the ocean at scattered entries along the Kapoho (pictured) and Ahalanui lobes.

A sand bar has built up at the end of the Pohoiki boat ramp, but the ramp itself remains intact and there has been no significant lava advance toward the ramp in recent days.

Fissure 8 may have slowed down, but HVO scientists are still on the ground in Leilani Estates, monitoring old ground cracks and marking ones that haven't been surveyed before. Monitoring these cracks over multiple days could detect any new signs of magma movement beneath the ground, one of the indicators that fissures might reactivate.

Today's morning overflight saw no new activity at any of the fissures in the lower East Rift Zone. Fissure 8 had only a sluggish lava puddle remaining in the cone, and other fissures, though steaming, showed no signs of reactivation.