As the lower Puna eruption changes the landscape day by day, a tool used to analyze ice is helping scientists learn more about lava.
The Glacier and Ice Surface Topography Interferometer, or GLISTIN, is an instrument pod mounted on a research plane that can measure changes in topography over large areas. As the name suggests, the instrument was designed for use on glaciers and ice sheets, but it is now being used to track the shifting topography of the lava flows.
The ASTER images, acquired on May 6, 2018, show different aspects of the eruption. A color composite depicts vegetation in red, and old lava flows in black and gray. Superimposed on the image in yellow are hotspots detected on the thermal infrared bands. The easternmost hot spots show the newly formed fissures and the lava flow spilling to the northwest.
Paul Lundgren, principal scientist at NASA’s Jet Propulsion Laboratory’s Earth Surface and Interior division, told the Tribune-Herald repeated scans of a landscape using GLISTIN allows scientists to determine the changes to topography over time. When used over the Kilauea flow, GLISTIN not only can map the flow, but determine its thickness.
“If we calculate the thickness, we can determine its volume, and if we know that, we can find out things like the effusion rate,” Lundgren said.
Ultimately, Lundgren said, GLISTIN can help scientists determine the “magma budget” of Kilauea: By determining the thickness of the lava, scientists can estimate how much magma has left the Kilauea magma chamber and how much remains.
“This is the first time it’s been applied to volcanoes, so it’s still experimental,” Lundgren said, adding that GLISTIN is intended primarily as a research tool and is not meant for rapid responses.
The Operational Land Imager (OLI) on Landsat 8 captured this false-color image of the lava flow during the nighttime on May 23, 2018. The image is based on OLI’s observations of shortwave infrared and green light (bands 6-5-3). The lava, which is approximately 1,170 degrees Celsius (2,140 degrees Fahrenheit) when it emerges from an active fissure, appears yellow. It was quite cloudy when the image was acquired, but a small break in the clouds made it possible to observe the lava. The purple areas surrounding the lava flow are clouds lit from below. The animation also makes use of a daytime-image from OLI, with information about the location of roads, coastlines, and Leilani Estates.
Therefore, U.S. Geological Survey has more efficient means of mapping the shape of the lava flow.
As an experimental tool, GLISTIN is still somewhat imperfect, Lundgren said. GLISTIN is designed to work with ice sheets up to 100 meters thick, while the lava flows east of Pu‘u ‘O‘o are 10 meters thick or less, which is close to the lower limit of what GLISTIN can detect.
Furthermore, the data from the different terrain can be difficult to parse. The radar and lidar systems used by GLISTIN are sensitive to the tops of trees, Lundgren said, and can incorrectly interpret treetops as the actual ground level. This can lead to data sets falsely indicating that ground level has decreased when, in reality, lava simply destroyed the trees in its way.
Despite these hiccups, Lundgren said GLISTIN hopefully will help researchers learn more about how Kilauea changes with each eruption.
GLISTIN is not NASA’s only tool employed to analyze the eruption. The Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, mounted on NASA’s Terra satellite, is being used to analyze sulfur dioxide emissions from Kilauea.
ASTER’s thermal infrared and visible and near-infrared sensor systems allow the sensor to analyze the Earth and its atmosphere through parts of the electromagnetic spectrum far outside of visible wavelengths. This allows it to image, among other things, emissions such as sulfur dioxide.
On May 6, 2018, at approximately 11 a.m. local time, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s Terra satellite captured this view of the island as it passed overhead. Much of the island was shrouded by clouds, including the fissure on its eastern point. However, an eruption plume is visible streaming southwest over the ocean. The MISR instrument is unique in that it has nine cameras that view Earth at different angles: one pointing downward, four at various angles in the forward direction, and four in the backward direction. This image shows the view from one of MISR’s forward-pointing cameras (60 degrees), which shows the plume more distinctly than the near-vertical views.
Vincent Realmuto of the Jet Propulsion Laboratory’s Earth Surface division said Kilauea is a site of increased interest for ASTER since the eruption began.
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The sensor is able to image the volcano approximately twice every 16 days and determine the concentration of sulfur dioxide emitted from the eruption sites.
In addition to sulfur dioxide, ASTER can map differences in the flow’s surface properties, mapping the area’s temperature and elevation as the flow progresses, Realmuto said.
KILAUEA VOLCANO (VNUM #332010)
19°25’16” N 155°17’13” W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: RED
Kīlauea Volcano Lower East Rift Zone
Eruption of lava continues in the area of Leilani Estates and Lanipuna Gardens.
Fissure 22 continues to erupt lava that is flowing southeast to the coast and the lava ocean entry. Fountains at Fissures 6 and 13 feed lava into a channel that reached the coast yesterday forming a second ocean entry.
Fissures 7 and 21 are feeding a perched lava pond and pāhoehoe flow that has advanced eastward covering most of the area bounded by Leilani Blvd, Mohala St., and the fissure line. Fissure 17 continues weak spattering, while Fissures 19 and 23 are no longer active.
HVO field crews are on site tracking the fountains, lava flows, and spattering from multiple fissures as conditions allow and reporting information to Hawaii County Civil Defense.
Volcanic gas emissions remain very high from the fissure eruptions.
Magma continues to be supplied to the lower East Rift Zone. Earthquake activity continues, but earthquake locations have not moved farther downrift in the past few days and the number of located earthquakes remains low.
Additional ground cracking and outbreaks of lava in the area of the active fissures are possible. Residents downslope of the region of fissures should heed all Hawaii County Civil Defense messages and warnings.
One volcano with two eruption locations miles apart. How is this possible?
Kīlauea Volcano is currently erupting at two locations: from Halema‘uma‘u, a crater within the summit caldera, and from the lower East Rift Zone (LERZ), in and near the Leilani Estates and Lanipuna subdivisions. How is it connected?
Following the collapse of Pu‘u ‘Ō‘ō on April 30, 2018, GPS, tiltmeters, and satellite radar (InSAR) data indicated contraction across the upper and middle East Rift Zone—evidence that magma was being withdrawn from this area. This was followed by expansion across the LERZ—evidence that magma was intruding into this part of the rift zone at depths of less than about 2 miles. The forceful widening of the LERZ continued through May 18, at which time a GPS site north of the intrusion stopped moving northwestward and stabilized.
At the summit, in early May (days after the collapse of Pu‘u ‘Ō‘ō) the lava lake level in Halema‘uma‘u began to drop as the summit area subsided at a high rate. The lava lake surface disappeared from view on about May 10, at a depth of more than 325 m (1,070 ft) below the Halema‘uma‘u crater floor. Subsidence of the summit area continues indicating that magma is moving from the summit magma reservoir and into the East Rift Zone. To date, geochemical analysis of erupted lava indicates that summit magma has not yet erupted from the LERZ fissures 1-23.
The illustration of Kīlauea Volcano shows the summit caldera to the lower East Rift Zone. Blue arrows indicate contraction across the upper and middle rift zone as magma withdrew from this area and moved down the rift zone beginning on April 30, 2018. Black arrows indicate expansion across the rift zone as magma intruded into the LERZ; the area stopped widening on about May 18. Also, beginning in early May, magma began moving from the summit reservoir into the East Rift Zone.
The article, “Ground- and space-based monitoring reveal where magma has moved under Kīlauea Volcano” is available on the USGS-Hawaiian Volcano Observatory News webpage, at https://volcanoes.usgs.gov/observatories/hvo/