A1 moonquakes, problems of determining their epicenters and mechanisms

Meißner, R.; Voss, Jason A.; Kaestle, H. J.

doi:10.1007/bf00562208

Cited by 8 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nearsurface moonquakes Nakamura, 1977a, Lammlein, 1977Goins et al, 1978b) are probably shallow seismic events. The most studied of lunar seismic events have been the deep-focus moonquakes (Meissner et al, 1973;Runcorn, 1974Runcorn, , 1977Lammlein et al, 1974;Goins et al, 1976aGoins et al, , 1978bLammlein, 1977;Toks6z et al, 1977;Nakamura, 1978;Smith et al, 1977).…”

Section: 2 Review Of Previous Workmentioning

confidence: 99%

“…The most numerous natural lunar seismic events are the deep focus (800-to 1100-kin depth) moonquakes, hereinafter referred to simply as moonquakes [Meissner et al, 1973;Runcorn, 1974Runcorn, , 1977Lammlein et al, 1974;Goins et al, 1976Goins et al, , .1981aGoins, 1978;Lammlein, 1977;Toks6z et al, 1977;Cheng and Toks6z, 1978;Nakamura, 1978;Smith et al, 1977]. They are different from nearly all terrestrial events in that they occur at about 100 distinct repeating focal locations (designated A1, A2, etc.)…”

Section: Seismogram and Eventmentioning

confidence: 99%

See 1 more Smart Citation

Lunar seismology: The internal structure of the Moon

Goins¹,

Dainty²,

Toksöz³

1981

J. Geophys. Res.

147

104

View full text Add to dashboard Cite

Tables A1–A4 and Figures A1–A3 are available with entire articleon microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C. 20009. Document J81‐003;$1.00. Payment must accompany order. The arrival times of direct P and S waves, measured on seismograms recorded from natural lunar seismic events, have been analyzed using linearized inversion and parameter search methods to simultaneously determine event locations, origin times, and structural parameters (seismic velocities). Polarization‐filtered record section plots are correlated with theoretical travel time curves to identify later phases and obtain additional structural and velocity information. Shear wave amplitudes plotted as a function of distance provide data on the existence and magnitude of seismic velocity gradients in the interior. These studies are used to delineate the structure of the moon below the crust to a depth of about 1100 km. This structure has been divided into an upper and a lower mantle. The upper mantle, from 60‐ to 400‐km depth, has average seismic wave velocities of Vp = 7.70 ±0.15 km/s and Vs = 4.45 ± 0.05 km/s with corresponding Q values (taken from the literature) of Qp ∼ 5000 and Qs ∼ 3000. The shear wave velocity decreases with a negative gradient of at most −6 × 10−4 km/s/km, implying a Vs variation of from 4.57 km/s at 60‐km depth to 4.37 km/s at 400‐km depth; this decrease can be accounted for by increasing temperature, and so no major compositional gradient is required in the upper mantle. A small negative P wave velocity gradient may also be present. Between 400‐ and 480‐km depth there is a transition zone with a sharply decreasing shear wave velocity and possibly an accompanying small decrease in Vp. The dominant shear velocity decrease may occur at a 480‐km interface and may represent a compositional change, although the effects of increased temperature cannot be totally ruled out. The lower mantle extends from 480‐km depth to at least 1100‐km depth; few seismic waves recorded by the lunar network penetrate below 1100 km. The average velocities are Vp = 7.6 ± 0.6 km/s and Vs = 4.2 ± 0.1 km/s. Q values (taken from the literature) are Qp ∼ 1500 and Qs ∼ 1000. Below 1100 km there is some indication that the attenuation may increase still further for shear waves, with Qs dropping to a few hundreds or less. This seismic model of the moon is well constrained, with uncertainties on the above values given explicitly by the analysis methods, and so it serves as a strong control on the present‐day lunar compositional and thermal structure.

show abstract

Section: 2 Review Of Previous Workmentioning

confidence: 99%

Section: Seismogram and Eventmentioning

confidence: 99%

Lunar seismology: The internal structure of the Moon

Goins¹,

Dainty²,

Toksöz³

1981

J. Geophys. Res.

147

104

View full text Add to dashboard Cite

show abstract

“…These moonquakes seem to be caused by a tide generated differential movement of inner low viscosity material and inhomogeneities in the outer more viscous part of the Afoonss mantle. It seems to be more a kind of tidal pumping of magma at great depths (Latham et al 1972) connected with inhomoge canism (Meissner et al 1973). This explanation would be in accordance with the temperatu calculations of Wood (1972) and Strangway & Sharpe (1974) as well as with the change in polarity of moonquake sources in the second stage of the 6 year beating period of lunar tides.…”

Section: Iscosity Models As Obtained From the Tem Perature Methodsmentioning

confidence: 99%

Lunar viscosity models

Meißner

1977

Phil. Trans. R. Soc. Lond. A

View full text Add to dashboard Cite

Viscosity values as estimated from isostatic processes and from temperature and melting point-depth relations show that the Moon’s outer layers are much more viscous than any geologic region on Earth. These high η -values are responsible for the survival of the very old lunar landscape. At depths below 500 km η -values increase and permit a limited convection. Moonquakes around 800 km depth seem to be connected with a limited range of viscosity values. A tentative relation between viscosity and seismic Q-values is presented.

show abstract

6.8 Lunar seismology

Meißner¹,

Janle²

Landolt-Börnstein - Group v Geophysics

View full text Add to dashboard Cite

A1 moonquakes, problems of determining their epicenters and mechanisms

Cited by 8 publications

References 7 publications

Lunar seismology: The internal structure of the Moon

Lunar seismology: The internal structure of the Moon

Lunar viscosity models

6.8 Lunar seismology

Contact Info

Product

Resources

About