Geological Society of America

T178 Friends of Hoth: Episode II—Icy Bodies of the Solar System (Posters)

Monday, 23 October 2017
9:00 AM - 6:30 PM
Halls 4EF

DETERMINING CERES' SUBSURFACE ICE CONTENT THROUGH THE PROPERTIES OF INTERMEDIATE LANDSLIDES

Paper number: T178-6
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Kayla Duarte Presenting Author
Georgia Institute of Technology, Atlanta, GA
C.T. Russell
University of California, Los Angeles, Los Angeles, CA
Carol A. Raymond
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA
James Wray
Georgia Institute of Technology, Atlanta, GA
Britney E. Schmidt
Georgia Institute of Technology, Atlanta, GA
Heather Chilton
Georgia Institute of Technology, Atlanta, GA
Ken L. Ferrier
Georgia Institute of Technology, Atlanta, GA
Kynan H.G. Hughson
Georgia Institute of Tecjnology, Atlanta, GA
Jennifer E.C. Scully
California Institute of Technology, Pasadena, CA
Hanna Sizemore
Planetary Science Institute, Tucson, AZ
Andreas Nathues
Goettingen
Thomas Platz
Max Planck Institute for Solar System Research, Göttingen

Abstract

Ceres, the largest body in the asteroid belt, is a primary focus of NASA’s Dawn mission, partially due to evidence for ice in Ceres’ surface and interior. Here we use Dawn Framing Camera data and build on earlier work using landslides to estimate ice content. Previously, three landslide types were identified using morphological criteria: type 1 (T1) have a thick, lobate toe, type 2 (T2) are thin and have a larger run out length than T1 landslides, and type 3 (T3) are more comparable to fluidized ejecta. However, landslides that do not fall cleanly into these groups, termed intermediate (IM), span a continuum between T1 and T2. Looking at these IM landslides allows us to better understand the relationship and progression between T1 and T2 and to identify any unique behaviors.

Our current analysis of IM landslides estimates the friction coefficient of Ceres’ near-surface material as the landslide deposit is emplaced via the ratio of landslide drop height to run-out length (H/L). We include both the conventional maximum (max) and our in-progress center of mass (CoM) approximation. To obtain H_Max/L_Max, we measure a topographic profile of the feature to attain its maximum length and height. H_CoM/L_CoM measurements are obtained using a profile by estimating the center of mass of the projected preexisting surface and the deposit. We have found some H/L values to be lower than those of landslides sourced in clay-rich materials, suggesting that the effective friction coefficient of these landslides is relatively low, potentially due to ice in the failed material. Further, the overlapping range of H/L ratios for T1 and T2 flows is reinforced by the continuous range of H/L values for IM landslides. This implies emplacement conditions are not uniquely linked to morphology, and may suggest temperature-dependent behavior. Overall, the major conclusions drawn from IM landslide analyses are 1) the idea that landslide mobility is loosely tied to morphology, and 2) that landslides on Ceres exhibit a continuous range of morphologies, with T1 and T2 representing end members of that continuum.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-306094

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