Figure 1 - uploaded by Philipp Gläser
Content may be subject to copyright.
Deployment of a seismic charge from the rover's seat during Apollo 17 Training (source: NASA).
Source publication
To support reanalysis of the Apollo 17 seismic data we determined the
ME-coordinates of the LSPE active sources and receivers using LROC NAC
and Apollo surface images.
Similar publications
In questo capitolo sono illustrate le campagne
sismometriche e le analisi geofisiche-sismologiche finalizzate alla stima sperimentale della
risposta di sito e delle caratteristiche amplificative della città di Umbertide e di alcuni siti in
località del territorio comunale. Lo studio è stato svolto congiuntamente dall’OGS, Sezione
Scientifica Ce...
Citations
... For example, Cooper et al. (1974) estimated the velocity structure up to about 2.0 km depth using seismic signals generated by explosions in the Apollo 17 lunar seismic profiling experiment (LSPE). Heffels et al. (2017) re-analyzed the LSPE data combined with the refined coordinates by Hasse et al. (2013). They concluded that the uppermost layers, called the regolith layers, consist of fine grains and fractured rocks with low elastic velocity (200 m/s-2.8 ...
One of the most critical issues associated with the analysis of lunar seismic data is the intense scattering, which prevents precise seismic phase identifications, thereby resulting in poor constraints on the internal structure of the Moon. Although some studies estimated subsurface scattering properties from analyses of the Apollo seismic data, the properties have large uncertainties and are still open issues to be resolved to improve the inner structure model of the Moon. While the previous studies tried to constrain the scattering features within the lunar crust mainly from data analysis, this study estimated them from a numerical approach. We constrained the scattering properties near Apollo 12 landing site by conducting seismic wave propagation simulations under various parameter settings and comparing the synthetics with the data. As a result, we succeeded in reproducing seismic signals excited by the Apollo artificial impacts. This led to a constraint on the scattering properties, such as typical scale and thickness of heterogeneity, around the Apollo 12 landing site. The derived structure suggests that the intense scattering structure exists down to 20 km at the northern portion of the region of the Apollo 12 landing site, and to 10 km at the southern region from the landing site. In addition, our model requires a smaller P‐ and S‐wave velocity ratio (1.2–1.4) compared with those conventionally considered (>1.73). This implies a dry and porous environment consistent with laboratory measurements of terrestrial samples and reasonable with the generalized lunar environment.
... Finally, the LSPE was also turned on from August 15, 1976to April 25, 1977 for passive observation. Haase et al. (2013) improved on the original approximate estimates of the coordinates for the dimensions of the geophone array and the locations of the explosives using images from Lunar Reconnaissance Orbiter. Heffels et al. (2017) used these coordinates to re-estimate the subsurface velocity structure. ...
... From Table 10-III inKovach et al. (1973). SeeHaase et al. (2013) for estimates of the coordinates.The Lunar Seismic Profiling Experiment (LSPE) used the same geophones as the Active Seismic Experiment (ASE). The logarithmic compression was similar to the active experiment. ...
Several seismic experiments were deployed on the Moon by the astronauts during the Apollo missions. The experiments began in 1969 with Apollo 11, and continued with Apollo 12, 14, 15, 16 and 17. Instruments at Apollo 12, 14, 15, 16 and 17 remained operational until the final transmission in 1977. These remarkable experiments provide a valuable resource. Now is a good time to review this resource, since the InSight mission is returning seismic data from Mars, and seismic missions to the Moon and Europa are in development from different space agencies. We present an overview of the seismic data available from four sets of experiments on the Moon: the Passive Seismic Experiments, the Active Seismic Experiments, the Lunar Seismic Profiling Experiment and the Lunar Surface Gravimeter. For each of these, we outline the instrumentation and the data availability.
We show examples of the different types of moonquakes, which are: artificial impacts, meteoroid strikes, shallow quakes (less than 200 km depth) and deep quakes (around 900 km depth). Deep quakes often occur in tight spatial clusters, and their seismic signals can therefore be stacked to improve the signal-to-noise ratio. We provide stacked deep moonquake signals from three independent sources in miniSEED format. We provide an arrival-time catalog compiled from six independent sources, as well as estimates of event time and location where available. We show statistics on the consistency between arrival-time picks from different operators. Moonquakes have a characteristic shape, where the energy rises slowly to a maximum, followed by an even longer decay time. We include a table of the times of arrival of the maximum energy tmax\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$t_{\max}$\end{document} and the coda quality factor Qc\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$Q_{c}$\end{document}.
Finally, we outline minimum requirements for future lunar missions to the Moon. These requirements are particularly relevant to future missions which intend to share data with other agencies, and set out a path for an International Lunar Network, which can provide simultaneous multi-station observations on the Moon.
... This allowed a detailed mapping of Apollo landing sites and reconstruction of the geometry of the deployed seismic array. Geometrically accurate coordinates (lat /long/heights) were determined by combination of these high-resolution orthoimages with Apollo surface panoramas taken by the astronauts (Haase et al., 2013). With this method it was possible to determine new geometrically accurate coordinates for six of the eight EPs. ...
... New LROC-derived coordinates of seismic equipment differ from previously published coordinates by up to 40 m. In addition, the new LROC-derived coordinates include topographic height information (differences in height in the range of 35 m (Haase et al., 2013)) not available before. ...
... The new Lunar Reconnaissance Orbiter Camera (LROC)-based point distances from Haase et al. (2013) are available for six of the eight Explosive Packages (EPs). Hence, to work with a self-consistent data set we only use the EPs where old and new coordinates are existent. ...
We re-analyzed Apollo 17 Lunar Seismic Profiling Experiment (LSPE) data to improve our knowledge of the subsurface structure of this landing site. We use new geometrically accurate 3-D positions of the seismic equipment deployed by the astronauts, which were previously derived using high-resolution images by Lunar Reconnaissance Orbiter (LRO) in combination with Apollo astronaut photography. These include coordinates of six Explosive Packages (EPs) and four geophone stations. Re-identified P-wave arrival times are used to calculate two- and three-layer seismic velocity models. A strong increase of seismic velocity with depth can be confirmed, in particular, we suggest a more drastic increase than previously thought.
For the three-layer model the P-wave velocities were calculated to 285, 580, and 1825 m/s for the uppermost, second, and third layer, respectively, with the boundaries between the layers being at 96 and 773 m depth.
When compared with results obtained with previously published coordinates, we find (1) a slightly higher velocity (+4%) for the uppermost layer, and (2) lower P-wave velocities for the second and third layers, representing a decrease of 34% and 12% for second and third layer, respectively. Using P-wave arrival time readings of previous studies, we confirm that velocities increase when changing over from old to new coordinates. In the three-layer case, this means using new coordinates alone leads to thinned layers, velocities rise slightly for the uppermost layer and decrease significantly for the layers below.
We re-analyze data from the Apollo 17 Lunar Seismic Profiling Experiment (LSPE) using updated locations of the applied explosive sources. Specifically, we complement our models with the previously missing coordinates and P-wave arrival times of Explosive Packages EP1 and EP7. We read new P-arrival times for all eight EP events, and solve for two- and three-layer seismic velocity models. We confirm a strong increase of seismic velocity with depth. In particular, we suggest a more drastic increase than was previously thought from post-mission coordinate information. For the three-layer model we find P-wave velocities of 315, 580, and 2680 m/s for the uppermost, second, and third layers respectively, with the transitions between the layers being at depths of 110 and 855 m. When compared with previous results, we find (1) a slightly higher velocity (+10.5%) for the uppermost layer, (2) no differences in velocity for the second layer, and a (3) significantly higher P-wave velocity for the third layer (+46.9%).
A Digital Terrain Model (DTM) of the Taurus-Littrow Valley with a 1.5 m/pixel resolution was derived from high resolution stereo images of the Lunar Reconnaissance Orbiter Narrow Angle Camera (LROC NAC) [1]. It was used to create a controlled LROC NAC ortho-mosaic with a pixel size of 0.5 m on the ground. Covering the entire Apollo 17 exploration site, it allows for determining accurate astronaut and surface feature positions along the astronauts' traverses when integrating historic Apollo surface photography to our analysis.
