Block-and-ash flow deposition: A conceptual model from a GPR survey on pyroclastic-flow deposits at Merapi Volcano, Indonesia

Gomez, Christopher; Lavigne, Franck; Hadmoko, Danang Sri; Lespinasse, N.; Wassmer, Patrick

doi:10.1016/j.geomorph.2009.03.024

Cited by 25 publications

(25 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also confirmed that almost all volcanic products were deposited at the western flank from the summit in a field survey in January 2008. This trend agrees with field observations made by Charbonnier and Gertisser (2008) and the ground-penetrating radar survey by Gomez et al (2009). Therefore, it is unlikely that volcanic products were deposited toward the east.…”

Section: Image Processing For Selected Sar Datasupporting

confidence: 90%

SAR- and gravity change-based characterization of the distribution pattern of pyroclastic flow deposits at Mt. Merapi during the past 10 years

et al. 2009

View full text Add to dashboard Cite

Mt. Merapi, Indonesia, is one of the most active and dangerous volcanoes in the Torrid Zone. This volcano has erupted frequently and has produced pyroclastic flows following the collapse of the summit lava dome. We used Synthetic Aperture Radar (SAR) data acquired by JERS-1 and RADARSAT-1 satellites from April 1996 to July 2006 to clarify the distribution patterns of the pyroclastic flow deposits. The extent of the deposits, termed P-zones, was accurately extracted by ratio operation and low-level feature extraction from SAR intensity images. These images highlighted temporal changes of the distribution area, perimeter, flow distance, included angle, and collapse direction. To validate the image-processing results, reflectance spectra of the rock samples collected after the eruption in June 2006 were measured in a laboratory. The reflectance spectra of all samples showed similar characteristics to the reference spectra, which were derived from atmospheric correction of Hyperion sensor image data covering the lava dome at the summit. Therefore, P-zones were confirmed to be the pyroclastic flow deposits originating from destruction of the lava dome at the summit. The image-processing results clarified that the extent of the distribution areas, perimeter, flow distances, and included angle of the P-zones were variable among the eruptions, while the collapse direction had a constant pattern. The collapse pattern followed a clockwise change from the south toward the west. By comparing the ratio maps of Bouguer gravity anomaly data in two periods, the change was interpreted to originate from the inclination of the conduit and the formation of shallow and deep magma reservoirs.

show abstract

Section: Image Processing For Selected Sar Datasupporting

confidence: 90%

SAR- and gravity change-based characterization of the distribution pattern of pyroclastic flow deposits at Mt. Merapi during the past 10 years

et al. 2009

View full text Add to dashboard Cite

show abstract

“…detection of block-and-ash fl ow structures at Merapi Volcano - Gomez et al, 2008Gomez et al, , 2009. For the present survey, we fi rst calibrated the GPR survey using the signal we obtained from a 7 m long and 2 m deep radargram within a lahar deposit terrace that was accessible on the outcrop scale.…”

Section: Methdologymentioning

confidence: 99%

“…We carried out a ground penetrating radar (GPR) survey 9·5 km from the summit of the volcano in the Curah Lengkong valley, which is located below the horseshoe-shaped summital rim, into which lahars fl ow several times a year (Gomez and Lavigne, 2009 (Lavigne and Suwa, 2004). Each event emplaces thick terraces deposits, which are the objects of our investigation.…”

Section: Introductionmentioning

confidence: 99%

Transverse architecture of lahar terraces, inferred from radargrams: preliminary results from Semeru Volcano, Indonesia

Gomez

Lavigne

2010

Earth Surf Processes Landf

Self Cite

View full text Add to dashboard Cite

Semeru Volcano is the highest mountain of Java (Indonesia), and a vulcanian explosion occurs every 15 minutes on average, since 1967. Thus a constantly renewed stock of material and the heavy monsoon rainfall [3700 mm yr −1 at 1500 m above sea level (a.s.l.)] provide a perfect setting for the study of lahars and their deposits. Hence, we examined the architecture of lahars' terraces 9·5 km from the summit in the Curah Lengkong Valley. We fi rst used ground penetrating radar (GPR) over vertical exposures of the lahars cut-bank terraces. This allowed us to better understand transversal radargrams across terraces, which are not visually accessible in the fi eld.Preliminary results from a single radargram are very instructive, since (1) they prove that the lateral architecture does not correspond to that observed from banks only; (2) we could observe the presence of lenses and stratigraphic discontinuities; (3) the setting of the various units can also help reconstruct deposition processes and the chronology of different units. In order to fi nalize these preliminary results, we however need to perform multiple GPR radargrams and provide a complete set of results. Copyright

show abstract

“…BAF are hot, small volume, mainly monomict volcaniclastic breccias (lava-blocks in ash matrix) (Michol et al, 2008) that could present tractional structures and graded bedding (Gomez et al, 2009). Radially oriented cooling joints in blocks (Stewart et al, 2003), breadcrust textures, thermal oxidation, and gas pipes are also common features that indicate the hot character of these deposits (Trofimovs et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

The Montesbelos mass-flow (southern Amazonian craton, Brazil): a Paleoproterozoic volcanic debris avalanche deposit?

Roverato¹

2016

Bull Volcanol

View full text Add to dashboard Cite

The present contribution documents the extremely well-preserved Paleoproterozoic architecture of the Montesbelos breccia (named here for the first time), which is interpreted as a rare example of a subaerial paleoproterozoic (>1.85 Ga) granular-dominated mass-flow deposit, few of which are recorded in the literature. Montesbelos deposit is part of the andesitic Sobreiro Formation located in the São Felix do Xingu region, southern Amazonian craton, northern Brazil. The large volume, high variability of textural features, presence of broken clasts, angular low sphericity fragments, mono-to heterolithic character, and the size of the outcrops point to a volcanic debris avalanche flow. Fluviatile sandy material and debris flows are associated with the deposit as a result of post-depositional reworking processes.

show abstract

Block-and-ash flow deposition: A conceptual model from a GPR survey on pyroclastic-flow deposits at Merapi Volcano, Indonesia

Cited by 25 publications

References 29 publications

SAR- and gravity change-based characterization of the distribution pattern of pyroclastic flow deposits at Mt. Merapi during the past 10 years

SAR- and gravity change-based characterization of the distribution pattern of pyroclastic flow deposits at Mt. Merapi during the past 10 years

Transverse architecture of lahar terraces, inferred from radargrams: preliminary results from Semeru Volcano, Indonesia

The Montesbelos mass-flow (southern Amazonian craton, Brazil): a Paleoproterozoic volcanic debris avalanche deposit?

Contact Info

Product

Resources

About