Multiscale and Multisensor Mapping of the 2018 Sierra Negra Eruption, Galápagos, Ecuador
Abstract
The 2018 eruption of Sierra Negra Volcano in the Galápagos, Ecuador produced ~200 x 109 m3 of lava in two pulses beginning 01 July and 31 July. The first pulse occurred from a series of fissures that began at the north rim of the caldera and propagated discontinuously to the NW. These caldera rim fissures were short-lived (<10 days) and produced 'a'a flows that advanced 2 to 7 km down the volcano flank to the north. The second pulse occurred on mid- to lower-flank vents, lasted 57 days and produced some flows that reached the ocean and extended the coastline by ~1km. In October 2018 a field expedition was conducted that used drones to map the vent regions and proximal lava flows at the caldera rim. Over a period of five days, we mapped an area of ~20 km2 at a horizontal resolution of 20 cm. These data are used to refine the map of flow boundaries, delineating the location of eruptive vents, scoria deposits, and lava channels. Flow mapping is aided by comparison of the new drone-derived DEM with a pre-eruption TanDEM-X DEM at 12m resolution. Simultaneously collected thermal imagery provides additional insight into flow boundaries as well as the thermal state of the new volcanic field four months post-eruption. We use the flow boundaries and vent locations to evaluate flow emplacement models and to test the impact of DEM resolution (drone-based and TanDEM-X). We also use the drone imagery to develop a machine learning algorithm for identification of surface deposits (e.g., lava textures, ages, and scoria deposits) to demonstrate efficient, automated interpretation. Lastly, we report on a newly developed lightweight, low-cost volcanic gas sensor system that was mounted to the drone and collected gas concentration data in situ over active fumaroles. Our results offer new insight into the dynamics and mechanics of the 2018 Sierra Negra eruption and approaches for drone-based eruption response.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.V23C..02S
- Keywords:
-
- 1030 Geochemical cycles;
- GEOCHEMISTRY;
- 1031 Subduction zone processes;
- GEOCHEMISTRY;
- 8414 Eruption mechanisms and flow emplacement;
- VOLCANOLOGY;
- 8485 Remote sensing of volcanoes;
- VOLCANOLOGY