Constructing a Probabilistic Seismic Hazard Analysis Framework for the Moon
Abstract
Introduction: Global coverage with high resolution images and altimetry data from the Lunar Reconnaissance Orbiter (LRO) spacecraft have enabled detailed mapping of both contractional and extensional tectonic features on the Moon including wrinkle ridges, graben, and over 3500 young lobate scarps [e.g., 1-3]. Lobate scarps (thrust fault scarps) in particular are widespread across the lunar surface [1-3] and are believed to have been active within the past $\sim$400 Ma, with some potentially still currently active [1, 4, 5]. The locations of the young fault scarps can now be combined with newly developed seismic ground motion shakemaps [1] and data from the Apollo-era seismic network on distributed seismicity and the nature of the near-subsurface structure [6-8]. These data and information collectively offer the components needed to develop a preliminary probabilistic seismic hazard analysis (PSHA) for the Moon. We explore the application of PSHA methods utilized in the nuclear industry [e.g., 9-11] and more broadly. These methods may provide a useful resource for evaluating seismic hazards on the lunar surface, both globally and at high priority landing sites and future locations of extended surface operations or permanent structures (for example near permanently shadowed regions (PSRs)). Such a hazard evaluation is potentially applicable to any terrestrial body with evidence of tectonic activity and is essential to support the future design and construction of structures, systems, and components [12], and to aid in the development of future seismic monitoring networks. Methods: Traditional PSHA calculations involve integrating information regarding the location and magnitude of possible seismic sources and their estimated frequencies of occurrence (seismic source model), estimates of ground motion attenuation (ground motion model), and the effect of the near-surface on the amplification of ground motions (site response model), to estimate the probability and severity of expected ground motion at a site of interest [9-11], and regional effects. Results of a PSHA are typically presented as a seismic hazard curve, which presents a measure of ground motion severity (e.g., peak ground acceleration) on one axis and the (annual) frequency of exceedance on the other axis (see [13-14]). The results of this analysis will demonstrate the development of preliminary hazard curves, which can be used to estimate seismic hazards. This analysis will also help target areas where additional orbital and/or in-situ data may be needed to develop a more robust PSHA for design purposes for future exploration. Acknowledgments: We thank the LRO science teams, engineers, and technical support personnel. Support provided by the NASA Solar System Exploration Research Virtual Institute (SSERVI) Cooperative Agreement NNH16ZDA001N, TREX team, and the SSERVI Grant 80NSSC19M0216, GEODES team. References: [1] Watters et al. (2019) Nature Geoscience, 12, 411-417 [2] Watters, T.R., et al. (2010) Science, 329, 936-940; [3] Watters, T.R., et al. (2015) Geology, 43, 851-854; [4] van der Bogert C. H. et al. (2018) Icarus, 306, 225-242. [5] Clark J. D. et al. (2015) LPSC XLVI, Abstract #1730. [6] Nakamura, Y. et al. (1979) Proc. Tenth Lunar Sci. Conf., 2299-2309 [7] Nakamura, Y. et al. (1981) Institute for Geophysics, Univ. of Texas, 188; [8] Nakamura, Y. (1982) J. Geophys. Res, 87; [9] American National Standards Institute (ANSI) / American Nuclear Society (ANS) Standard 2.29, Probabilistic Seismic Hazard Analysis (2008); [10] Nuclear Regulatory Commission, Regulatory Guide 1.208 (2007); [11] Nuclear Regulatory Commission NUREG-1350, Volume 27 (2016); [12] Justh, H. et al. (2016) Natural Environments Definition for Design. NASA/TM—2016-218229. [13] Nuclear Regulatory Commission NUREG-2213 (2018); [14] Baker, J. (2013), Probablistic Seismic Hazard Analysis, White Paper Version 2.0.1, 79 pages.
- Publication:
-
43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E.358B