Isostatic Compensation of the Lunar Highlands

Isostatic Compensation of the Lunar Highlands The lunar highlands are isostatically compensated at large horizontal scales, but the specific compensation mechanism has been difficult to identify. With topographic data from the Lunar Orbiter Laser Altimeter and gravity data from the Gravity Recovery and Interior Laboratory, we investigate support of highland topography. Poor correlation between crustal density and elevation shows that Pratt compensation is not important in the highlands. Using spectrally weighted admittance, we compared observed values of geoid‐to‐topography ratio (GTR) with those predicted by isostatic models. Observed GTRs are 25.8+7.5–5.7 m/km for the nearside highlands and 39.3+5.7–6.2 m/km for the farside highlands. These values are not consistent with flexural compensation of long‐wavelength topography or Airy isostasy defined under an assumption of equal mass in crustal columns. Instead, the observed GTR values are consistent with models of Airy compensation in which isostasy is defined under a requirement of equal pressures at equipotential surfaces at depth. The gravity and topography data thus reveal that long‐wavelength topography on the Moon is most likely compensated by variations in crustal thickness, implying that highland topography formed early in lunar history before the development of a thick elastic lithosphere. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Geophysical Research: Planets Wiley

Loading next page...
 
/lp/wiley/isostatic-compensation-of-the-lunar-highlands-e3kG1Jjmk3
Publisher
Wiley
Copyright
©2018. American Geophysical Union. All Rights Reserved.
ISSN
2169-9097
eISSN
2169-9100
D.O.I.
10.1002/2017JE005362
Publisher site
See Article on Publisher Site

Abstract

The lunar highlands are isostatically compensated at large horizontal scales, but the specific compensation mechanism has been difficult to identify. With topographic data from the Lunar Orbiter Laser Altimeter and gravity data from the Gravity Recovery and Interior Laboratory, we investigate support of highland topography. Poor correlation between crustal density and elevation shows that Pratt compensation is not important in the highlands. Using spectrally weighted admittance, we compared observed values of geoid‐to‐topography ratio (GTR) with those predicted by isostatic models. Observed GTRs are 25.8+7.5–5.7 m/km for the nearside highlands and 39.3+5.7–6.2 m/km for the farside highlands. These values are not consistent with flexural compensation of long‐wavelength topography or Airy isostasy defined under an assumption of equal mass in crustal columns. Instead, the observed GTR values are consistent with models of Airy compensation in which isostasy is defined under a requirement of equal pressures at equipotential surfaces at depth. The gravity and topography data thus reveal that long‐wavelength topography on the Moon is most likely compensated by variations in crustal thickness, implying that highland topography formed early in lunar history before the development of a thick elastic lithosphere.

Journal

Journal of Geophysical Research: PlanetsWiley

Published: Jan 1, 2018

Keywords: ; ; ; ; ;

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off