Geology Reports⌕ Search

USGS · 70225591

Tracking secondary lahar flow paths and characterizing pulses and surges using infrasound array networks at Volcán de Fuego, Guatemala

Abstract

Lahars are one of the greatest hazards at many volcanoes, including Volcán de Fuego (Guatemala). On 1 December 2018 at 8:00pm local Guatemala time (2:00:00 UTC), an hour-long lahar event was detected at Volcán de Fuego by two permanent seismo-acoustic stations along the Las Lajas channel on the southeast side. To establish the timing, duration, and speed of the lahar, infrasound array records were examined to identify both the source direction(s) and the correlated energy fluctuations at the two stations. Co-located seismic and acoustic signals were also examined, which indicated at least 5 distinct energy pulses within the lahar record. We infer that varying sediment load and/or changes in flow velocity is shown by clear fluctuations in the acoustic and seismic power recorded at one of the stations. This particular event studied with infrasound provides insight into how lahars occur around Volcán de Fuego.

Explore related subjects

90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 14.396773712446521° to 14.500170089974075° latitude; -90.94242095947266° to -90.81298828125° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ashley Bosa, Jeffery Johnson, Silvio DeAngelis, John J. Lyons, Amilcar Roca, Jacob F. Anderson, Armando Pineda. 2021-10-25. Tracking secondary lahar flow paths and characterizing pulses and surges using infrasound array networks at Volcán de Fuego, Guatemala. https://doi.org/10.30909/vol.04.02.239256

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

The fluorine dichotomy: Amphibole control on fluorine availability during magmatic differentiation

Experimental and observational evidence suggests that water and fluorine (F) are incompatible in silicate minerals and originate from similar sources in the mantle. This, in turn, suggests that F and water should coevolve in magmatic systems. However, hydrous subduction zone (“arc”) magmas are depleted in F relative to anhydrous magmas. We explore this apparent dichotomy in fluorine’s behavior by examining amphibole, which preferentially incorporates F into its crystal structure. By developing a parametrized fluorine amphibole/silicate melt partition coefficient for F, we show that F concentrations in calculated equilibrium melts in arc systems do not increase with differentiation. This indicates that F behaves compatibly in hydrous arc magmas due to sequestration in amphibole-bearing arc cumulates. In dry magmatic systems, where amphibole does not crystallize, we show that F behaves incompatibly during differentiation, resulting in F enrichment in evolved magmas. These results have implications for the formation of ore deposits associated with elements that complex with F, such as rare-earth elements.

Volcanica↗

A scanning electron microscope-energy dispersive spectrometry (SEM-EDS) method for the quantitative analysis of common volcanic phases

In situ microanalysis by X-ray spectrometry is a fundamental geochemical technique for volcanology and the geosciences generally and typically performed using an electron microprobe (EPMA) equipped with wavelength dispersive spectrometers (WDS). The related technique of energy dispersive spectrometry (EDS), implemented using either EPMA or a scanning electron microscope (SEM), offers advantages in throughput, simplicity, and cost, yet has historically been relegated to qualitative tasks. We present a quantitative EDS procedure implemented using a W-source SEM and a moderate size silicon drift EDS detector applied to common volcanic materials. Glass and mineral standard data demonstrate that the accuracy and precision of this method is comparable to EPMA–WDS. We show that electron beam damage can be mitigated in volcanic glass through sample-specific optimizations without the need for a time-dependent intensity correction. Our implementation using a relatively inexpensive instrument can potentially increase the accessibility of high-quality, quantitative X-ray microanalysis of major and minor elements.

Volcanica↗

Relating glassy rind thicknesses to ambient air temperatures at the Lost Jim flow field in the Imuruk Lake volcanic field, Alaska

The Lost Jim flow field, in the Imuruk Lake volcanic field, Alaska, extends west ~34 km from a single vent, crossing subarctic tundra and currently touches several lakes and streams. The weighted mean of five 36Cl cosmogenic exposure ages from the Lost Jim pāhoehoe flow is 7.73 ± 0.37 ka, indicating this eruption occurred substantially after the eruption of the underlying Camille flow, which was emplaced at 39.7 ± 1.3 ka. Paleoclimate records indicate the period when the Lost Jim flow field was emplaced was after deglaciation, and the climate was similar to today. We propose that the emplacement of lava in these cold subarctic conditions can lead to faster cooling of the lava surface compared to lava emplaced in warmer locations such as mid- latitude cold deserts. Glass abundance in the outermost rinds at the Lost Jim flow field was on average 74 % with 6.4 mm thick rims, compared to 60 % with 2.9 mm rims for cold mid-latitude desert samples. We interpret increased glass content as a proxy for rapid cooling likely occurring partly during winter. Glassiness values varied less across vent, margin, and mid-flow locations when compared to the mid-latitude flows suggesting the Lost Jim flow field was broadly impacted by the subarctic climate as opposed to responding to local microclimates. Our results indicate that lava glassiness may be a useful environmental indicator of cooler (in this case subarctic) conditions.

Alaska↗