Ash from Kilauea Eruption Viewed by NASA's MISR
Ash from the Kilauea Eruption 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.
The information from the images acquired at different view angles is used to calculate the height of the plume, results of which are superimposed on the right-hand image. The top of the plume near the fissure is at approximately 6,500 feet (2,000 meters) altitude, and the height of the plume decreases as it travels south and west. These relatively low altitudes mean that the ash and sulfur dioxide remained near the ground, which can cause health issues for people on the island downwind of the eruption.
Image/Article Credit: NASA/GSFC/LaRC/JPL-Caltech, MISR Team
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To determine the influence of volcanic eruptions, accurate plume heights are needed, but are difficult to obtain due to the hazardous nature of such eruptions. Stereo images from MISR make it possible to map plume heights in ongoing eruptions using parallax in the stereo imagery. Multi-angle images make it possible to distinguish eruptive plumes from metrological clouds and remobilized ash. The visual characteristics of the plume indicate little or no ash components. At this altitude, the direct (ash fall) and indirect (surface temperature) effects are likely to remain local-regional. Activity remains high at Kilauea on subsequent days, with the potential for ongoing eruptions to cause significant regional hazards to populations and aviation.
Volcanic eruption plume from Kilauea Volcano, Hawaii
MISR Active Aerosol Plume-Height (AAP) Project 6 May 2018
Credit: V. Flower, R. Kahn, J. Limbacher / NASA GSFC
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