Acid lava flow structure

Over 500 million people live in proximity of an active volcano globally. Although lava flows rarely endanger human life, they often destroy critical infrastructure. Advancing our understanding of lava flow dynamics is therefore critical to developing accurate hazard assessment, with key socio-economic impacts for many communities. This work focuses on basaltic lava rheology, which exerts a first-order control on flow dynamics and is reflected in lava morphology. In particular, I address the following research questions: (1) How does the rheology of active flows evolve during emplacement; and (2) How can we use flow morphology to infer the rheology of inactive flows? ... At Piton de La Fournaise (La Rï¿½union, FR DOM), I addressed the longstanding question of how pre-existing topography controls lava flow system structure in volume-limited flows (Soldati et al., accepted). I concluded that a steep slope results in a single, stable channel, whereas a gentle slope results in an unstable, braided channel. The findings of this study allow us to interpret and explain the observed flow structure on the basis of pre-existing volcano topography, and to forecast future flow structure. This allowed me to determine that rheology neither affects nor is affected by flow system configuration.

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ELEMENTAL AND TOPOGRAPHIC MAPPING OF LAVA FLOWSTRUCTURES IN MARE SERENITATIS ON THE MOON

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w1-163-2017 ◽

2017 ◽

Vol XLII-3/W1 ◽

pp. 163-170 ◽

Cited By ~ 2

Author(s):

C. Wöhler ◽

A. Grumpe ◽

D. Rommel ◽

M. Bhatt ◽

U. Mall

Keyword(s):

Lava Flow ◽

Flow Structure ◽

Hyperspectral Image ◽

Image Data ◽

Elemental Abundance ◽

Lava Flows ◽

Stereo Image ◽

The Moon ◽

Lunar Reconnaissance Orbiter ◽

Mare Serenitatis

The detection of lunar lava flows based on local morphology highly depends on the available images. The thickness of lava flows, however, has been studied by many researchers and lunar lava flows are shown to be as thick as 200&thinsp;m. Lunar lava flows are supposed to be concentrated on the northwestern lunar nearside. In this study we present elemental abundance maps, a petrological map and a digital terrain model (DTM) of a lava flow structure in northern Mare Serenitatis at (18.0&deg;&thinsp;E, 32.4&deg;&thinsp;N) and two possible volcanic vents at (11.2&deg;&thinsp;E, 24.6&deg;&thinsp;N) and (13.5&deg;&thinsp;E, 37.5&deg;&thinsp;N), respectively. Our abundance maps of the refractory elements Ca, Mg and our petrological map were obtained based on hyperspectral image data of the Moon Mineralogy Mapper (M3) instrument. Our DTM was constructed using GLD100 data in combination with a shape from shading based method to M3 and Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) image data. The obtained NAC-based DEM has a very high effective resolution of about 1&ndash;2&thinsp;m which comes close to the resolution of the utilized NAC images without requiring intricate processing of NAC stereo image pairs. As revealed by our elemental maps and DEM, the examined lava flow structure occurs on a boundary between basalts consisting of low-Ca/high-Mg pyroxene and high-Ca/low-Mg pyroxene, respectively. The total thickness of the lava flow is about 100&thinsp;m, which is a relatively large value, but according to our DEM the lava flow may also be composed of two or more layers.

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