Slumped Crater Wall | ScienceGate

Absorption features that occur in reflectance spectra are a sensitive indicator of mineralogy and chemical composition for a wide variety of materials. The investigation of the mineralogy and chemical composition of surfaces give information about the origin and evolution of planetary bodies. On Mars, the processes of formation of different types of clay minerals result from different types of wet conditions viz. hydrothermalism, subsurface/groundwater weathering, surface alteration etc. The image analyzed in the present study was frt000947f- 164-trr3 (−27.87N–65.06E). Through the spectral stratigraphic characterization along a crater wall, eight (8) different layers were identified considering the spectral variability and their position. In Hellas Planitia, the alteration minerals identified by CRISM based on distinctive absorptions from 0.4 to3.9 μm include Al-rich smectite, montmorillonite, phyllosilicate mineral at 2.2 μm and 2.35 μm, including strong absorption feature noticed at 1.9 μm. We conclude that the layers exposed in the crater wall help characterize the compositional stratigraphy for confirming the presence of hydrated minerals in this region as an outcome of geohydrological weathering process.

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Incipient Glacier Development within Katmai Caldera, Alaska

Journal of Glaciology ◽

10.3189/s0022143000024643 ◽

1957 ◽

Vol 3 (21) ◽

pp. 13-17

Author(s):

E. H. Muller ◽

H. W. Coulter

Keyword(s):

Sea Level ◽

Wall Rock ◽

Crater Wall ◽

The South ◽

The Past ◽

The North ◽

South West ◽

Direction Of Movement ◽

North And South

AbstractAn unusual opportunity for the study of glaciers in the process of development is afforded in Katmaicaldera in south-western Alaska. A violent eruption in 1912 destroyed the summit of glacier-clad Mount Katmai, creating a caldera 4 km. wide and 800 m. deep. Ice cliffs produced by beheading of the glaciers have since thinned and shrunk away from the rim of the caldera, except in the south-west. There, local reversal of direction of movement has resulted in an ice fall which descends part way down the crater wall. In the past thirty years two small glaciers have formed, near 1525 m. above sea level, within the caldera on large masses of slumped wall-rock below the north and south rims respectively. Elsewhere the sheer walls of the crater descend so steeply to the level of the caldera lake that permanent snowbanks cannot accumulate. The lake, which continues to rise at a rate of more than five meters per year, is at present the primary deterring factor in glacier development in the caldera.

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Terraced Crater Wall (Mass Wasting)

Encyclopedia of Planetary Landforms ◽

10.1007/978-1-4614-9213-9_361-1 ◽

2014 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Gareth S. Collins

Keyword(s):

Crater Wall ◽

Mass Wasting ◽

Wall Mass

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Crater Wall Flow-Like Features (Moon, Asteroids)

Encyclopedia of Planetary Landforms ◽

10.1007/978-1-4614-3134-3_106 ◽

2015 ◽

pp. 445-450

Author(s):

Tamás Börzsönyi ◽

Henrik Hargitai

Keyword(s):

Crater Wall ◽

Wall Flow

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Emplacement of a silicic lava dome through a crater glacier: Mount St Helens, 2004–06

Annals of Glaciology ◽

10.3189/172756407782282426 ◽

2007 ◽

Vol 45 ◽

pp. 14-20 ◽

Cited By ~ 3

Author(s):

Joseph S. Walder ◽

Richard G. LaHusen ◽

James W. Vallance ◽

Steve P. Schilling

Keyword(s):

Lava Dome ◽

Thick Layer ◽

Drainage Network ◽

Strain Rates ◽

Crater Wall ◽

Groundwater System ◽

Speed Up ◽

Speed Fluctuations ◽

First Time ◽

Mount St Helens

AbstractThe process of lava-dome emplacement through a glacier was observed for the first time after Mount St Helens reawakened in September 2004. The glacier that had grown in the crater since the cataclysmic 1980 eruption was split in two by the new lava dome. The two parts of the glacier were successively squeezed against the crater wall. Photography, photogrammetry and geodetic measurements document glacier deformation of an extreme variety, with strain rates of extraordinary magnitude as compared to normal alpine glaciers. Unlike normal temperate glaciers, the crater glacier shows no evidence of either speed-up at the beginning of the ablation season or diurnal speed fluctuations during the ablation season. Thus there is evidently no slip of the glacier over its bed. The most reasonable explanation for this anomaly is that meltwater penetrating the glacier is captured by a thick layer of coarse rubble at the bed and then enters the volcano’s groundwater system rather than flowing through a drainage network along the bed.

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Incipient Glacier Development within Katmai Caldera, Alaska

Journal of Glaciology ◽

10.1017/s0022143000024643 ◽

1957 ◽

Vol 3 (21) ◽

pp. 13-17 ◽

Cited By ~ 8

Author(s):

E. H. Muller ◽

H. W. Coulter

Keyword(s):

Sea Level ◽

Wall Rock ◽

Crater Wall ◽

The South ◽

The Past ◽

The North ◽

South West ◽

Direction Of Movement ◽

North And South

Abstract An unusual opportunity for the study of glaciers in the process of development is afforded in Katmaicaldera in south-western Alaska. A violent eruption in 1912 destroyed the summit of glacier-clad Mount Katmai, creating a caldera 4 km. wide and 800 m. deep. Ice cliffs produced by beheading of the glaciers have since thinned and shrunk away from the rim of the caldera, except in the south-west. There, local reversal of direction of movement has resulted in an ice fall which descends part way down the crater wall. In the past thirty years two small glaciers have formed, near 1525 m. above sea level, within the caldera on large masses of slumped wall-rock below the north and south rims respectively. Elsewhere the sheer walls of the crater descend so steeply to the level of the caldera lake that permanent snowbanks cannot accumulate. The lake, which continues to rise at a rate of more than five meters per year, is at present the primary deterring factor in glacier development in the caldera.

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