CaltechAUTHORS
  A Caltech Library Service

Innovative Approaches for Seismic Studies of Mars (Invited)

Banerdt, B. (2010) Innovative Approaches for Seismic Studies of Mars (Invited). Transactions - American Geophysical Union . U41A-04. ISSN 0002-8606. http://resolver.caltech.edu/CaltechAUTHORS:20160226-160425182

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20160226-160425182

Abstract

In addition to its intrinsic interest, Mars is particularly well-suited for studying the full range of processes and phenomena related to early terrestrial planet evolution, from initial differentiation to the start of plate tectonics. It is large and complex enough to have undergone most of the processes that affected early Earth but, unlike the Earth, has apparently not undergone extensive plate tectonics or other major reworking that erased the imprint of early events (as evidenced by the presence of cratered surfaces older than 4 Ga). The martian mantle should have Earth-like polymorphic phase transitions and may even support a perovskite layer near the core (depending on the actual core radius), a characteristic that would have major implications for core cooling and mantle convection. Thus even the most basic measurements of planetary structure, such as crustal thickness, core radius and state (solid/liquid), and gross mantle velocity structure would provide invaluable constraints on models of early planetary evolution. Despite this strong scientific motivation (and several failed attempts), Mars remains terra incognita from a seismic standpoint. This is due to an unfortunate convergence of circumstances, prominent among which are our uncertainty in the level of seismic activity and the relatively high cost of landing multiple long-lived spacecraft on Mars to comprise a seismic network for body-wave travel-time analysis; typically four to ten stations are considered necessary for this type of experiment. In this presentation I will address both of these issues. In order to overcome the concern about a possible lack of marsquakes with which to work, it is useful to identify alternative methods for using seismic techniques to probe the interior. Seismology without quakes can be accomplished in a number of ways. “Unconventional” sources of seismic energy include meteorites (which strike the surface of Mars at a relatively high rate), artificial projectiles (which can supply up to 1010 J of kinetic energy), seismic “hum” from meteorological forcing, and tidal deformation from Phobos (with a period around 6 hours). Another means for encouraging a seismic mission to Mars is to promote methods that can derive interior information from a single seismometer. Fortunately many such methods exist, including source location through P-S and back-azimuth, receiver functions, identification of later phases (PcP, PKP, etc.), surface wave dispersion, and normal mode analysis (from single large events, stacked events, or background noise). Such methods could enable the first successful seismic investigation of another planet since the Apollo seismometers were turned off almost 35 years ago.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://adsabs.harvard.edu/abs/2010AGUFM.U41A..04BADSAbstract
https://www.agu.org/meetings/fm10/OrganizationConference Website
Additional Information:© 2010 American Geophysical Union.
Group:Keck Institute for Space Studies
Subject Keywords:PLANETARY SCIENCES: SOLID SURFACE PLANETS / Interiors, PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS / Mars, SEISMOLOGY / General or miscellaneous
Record Number:CaltechAUTHORS:20160226-160425182
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20160226-160425182
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:64823
Collection:CaltechAUTHORS
Deposited By: Colette Connor
Deposited On:02 Mar 2016 00:26
Last Modified:02 Mar 2016 00:26

Repository Staff Only: item control page