Showing posts with label Thrust Faults. Show all posts
Showing posts with label Thrust Faults. Show all posts

Thursday, December 12, 2013

Ghost Crater


Mercury's surface has been extensively modified by tectonic activity. Giant thrust faults are thought to be the result of global cooling and contraction of the planet, and Mercury's smooth plains in particular are folded and wrinkled. With the Sun very low in the sky, the complexity of tectonic features in the northern volcanic plains is especially apparent. The wrinkle-ridge ring (also known as a "ghost crater") on the eastern edge of the scene was also captured here (see PIA15636) at more moderate illumination angles.

This image was acquired as part of MDIS's high-incidence-angle base map. The high-incidence-angle base map complements the surface morphology base map of MESSENGER's primary mission that was acquired under generally more moderate incidence angles. High incidence angles, achieved when the Sun is near the horizon, result in long shadows that accentuate the small-scale topography of geologic features. The high-incidence-angle base map was acquired with an average resolution of 200 meters/pixel.

Date acquired: November 12, 2013
Image Mission Elapsed Time (MET): 26543953
Image ID: 5181050
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 80.04°
Center Longitude: 86.24° E
Resolution: 230 meters/pixel
Scale: Scene is 125 km (78 miles) from top to bottom
Incidence Angle: 90.7°
Emission Angle: 49.8°
Phase Angle: 140.6°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Thursday, March 7, 2013

Thrust Fault Scarp on Mercury


The figure above shows an oblique view of a 280 km long scarp. The color scale on this figure represents elevation in which red is high and blue is low. This scarp is interpreted to be a surface-breaking thrust fault. Thrust faults are surface manifestations of the shrinkage of the planet resulting from the cooling of its interior. Notice that the terrain on the left side of the scarp stands about 2 km higher than that of the right side of the scarp. To give you a sense of the scale of this scarp, the state of Delaware has been superposed on the figure.

Center Latitude: 58.18°
Center Longitude: 307.69° E
Scale: The crater that is being cross-cut by this scarp is about 108 km (67 mi.) in diameter.

Illustration credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington