Publications
Filter Total Items: 922
Modeling the development of martian sublimation thermokarst landforms
Sublimation-thermokarst landforms result from collapse of the surface when ice is lost from the subsurface. On Mars, scalloped landforms with scales of decameters to kilometers are observed in the mid-latitudes and considered likely thermokarst features. We describe a landscape evolution model that couples diffusive mass movement and subsurface ice loss due to sublimation. Over periods of tens of
Authors
Colin M. Dundas, Shane Byrne, Alfred S. McEwen
Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale crater, Mars
The landforms of northern Gale crater on Mars expose thick sequences of sedimentary rocks. Based on images obtained by the Curiosity rover, we interpret these outcrops as evidence for past fluvial, deltaic, and lacustrine environments. Degradation of the crater wall and rim probably supplied these sediments, which advanced inward from the wall, infilling both the crater and an internal lake basin
Authors
J.P. Grotzinger, S. Gupta, M. C. Malin, D. M. Rubin, J. Schieber, K. Siebach, D.Y. Sumner, K.M. Stack, A.R. Vasavada, R.E. Arvidson, F. Calef, Lauren A. Edgar, W. F. Fischer, J.A. Grant, J.L. Griffes, L.C. Kah, M.P. Lamb, K.W. Lewis, N. Mangold, M.E. Minitti, M.C. Palucis, M. Rice, R.M.E. Williams, R.A. Yingst, D. Blake, D. Blaney, P. Conrad, J.A. Crisp, W. E. Dietrich, G. Dromart, K.S. Edgett, R.C. Ewing, R. Gellert, J.A. Hurowitz, G. Kocurek, P.G. Mahaffy, M.J. McBride, S. M. McLennan, M.A. Mischna, D. Ming, R.E. Milliken, H. Newsom, D. Oehler, T. J. Parker, D. Vaniman, R. C. Wiens, S. A. Wilson
Hydrothermal alteration and diagenesis of terrestrial lacustrine pillow basalts: Coordination of hyperspectral imaging with laboratory measurements
We investigate an outcrop of ∼187 Ma lacustrine pillow basalts of the Talcott Formation exposed in Meriden, Connecticut, USA, focusing on coordinated analyses of one pillow lava to characterize the aqueous history of these basalts in the Hartford Basin. This work uses a suite of multidisciplinary measurements, including hyperspectral imaging, other spectroscopic techniques, and chemical and minera
Authors
Rebecca N Greenberger, John F Mustard, Edward A. Cloutis, Paul Mann, Janette H. Wilson, Roberta L Flemming, Kevin Robertson, Mark R Salvatore, Christopher Edwards
Carbon sequestration on Mars
No abstract available.
Authors
Christopher S. Edwards, Bethany L. Ehlmann
The importance of dunes on a variety of planetary surfaces
Scientists observe aeolian bed forms, or dune-like structures, throughout the solar system in a range of locations, from bodies with only transient atmospheres, such as comets, to places with thick atmospheres, such as Venus and the Earth’s ocean floor. Determining the source of sand and the different dune formations that result are thus important to understanding solar system and planetary evolut
Authors
Timothy N. Titus, James R. Zimbelman, Jani Radebaugh
Examining spectral variations in localized lunar dark mantle deposits
The localized lunar dark mantle deposits (DMDs) in Alphonsus, J. Herschel, and Oppenheimer craters were analyzed using visible-near-infrared spectroscopy data from the Moon Mineralogy Mapper. Spectra of these localized DMDs were analyzed for compositional and mineralogical variations within the deposits and were compared with nearby mare basalt units. Spectra of the three localized DMDs exhibited
Authors
Erica Jawin, Sebastien Besse, Lisa R. Gaddis, Jessica Sunshine, James W. Head, Sara Mazrouei
Constraining the heat flux between Enceladus’ tiger stripes: numerical modeling of funiscular plains formation
The Cassini spacecraft’s Composite Infrared Spectrometer (CIRS) has observed at least 5 GW of thermal emission at Enceladus’ south pole. The vast majority of this emission is localized on the four long, parallel, evenly-spaced fractures dubbed tiger stripes. However, the thermal emission from regions between the tiger stripes has not been determined. These spatially localized regions have a unique
Authors
Michael T. Bland, William B. McKinnon, Paul M. Schenk
Slope activity in Gale crater, Mars
High-resolution repeat imaging of Aeolis Mons, the central mound in Gale crater, reveals active slope processes within tens of kilometers of the Curiosity rover. At one location near the base of northeastern Aeolis Mons, dozens of transient narrow lineae were observed, resembling features (Recurring Slope Lineae) that are potentially due to liquid water. However, the lineae faded and have not recu
Authors
Colin M. Dundas, Alfred S. McEwen
Temperature profile around a basaltic sill intruded into wet sediments
The transfer of heat into wet sediments from magmatic intrusions or lava flows is not well constrained from field data. Such field constraints on numerical models of heat transfer could significantly improve our understanding of water–lava interactions. We use experimentally calibrated pollen darkening to measure the temperature profile around a basaltic sill emplaced into wet lakebed sediments. I
Authors
Leslie Baker, Andrew Bernard, William C. Rember, Moses P. Milazzo, Colin M. Dundas, Oleg Abramov, Laszlo P. Kestay
Curiosity’s robotic arm-mounted Mars Hand Lens Imager (MAHLI): Characterization and calibration status
MAHLI (Mars Hand Lens Imager) is a 2-megapixel, Bayer pattern color CCD camera with a macro lens mounted on a rotatable turret at the end of the 2-meters-long robotic arm aboard the Mars Science Laboratory rover, Curiosity. The camera includes white and longwave ultraviolet LEDs to illuminate targets at night. Onboard data processing services include focus stack merging and data compression. Here
Authors
Kenneth S. Edgett, Michael A. Caplinger, Justin N. Maki, Michael A. Ravine, F. Tony Ghaemi, Sean McNair, Kenneth E. Herkenhoff, Brian M. Duston, Reg G. Wilson, R. Aileen Yingst, Megan R. Kennedy, Michelle E. Minitti, Aaron J. Sengstacken, Kimberley D. Supulver, Leslie J. Lipkaman, Gillian M. Krezoski, Marie J. McBride, Tessa L. Jones, Brian E. Nixon, Jason K. Van Beek, Daniel J. Krysak, Randolph L. Kirk
Evolution of Mars’ Northern Polar Seasonal CO2 deposits: variations in surface brightness and bulk density
Small scale variations of seasonal ice are explored at different geomorphic units on the Northern Polar Seasonal Cap (NPSC). We use seasonal rock shadow measurements, combined with visible and thermal observations, to calculate density over time. The coupling of volume density and albedo allows us to determine the microphysical state of the seasonal CO2 ice. We find two distinct endmembers across
Authors
Christopher P. Mount, Timothy N. Titus
The U.S. Geological Survey Geologic Collections Management System (GCMS)—A master catalog and collections management plan for U.S. Geological Survey geologic samples and sample collections
**Updated guidance is available in USGS Instructional Memorandum CSS 2019-01.**AbstractThe U.S. Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of earth materials collected by research personnel over the course of its history. In 2006, a Geologic Collections Inventory was conducted within the USGS Geology Discipline to determine the
Authors