Difference between revisions of "September 13, 2010"
| (3 intermediate revisions by the same user not shown) | |||
| Line 6: | Line 6: | ||
<em>image from [mailto:s.weider@ucl.ac.uk Weider and colleagues]; Icarus (2010)</em><br /> | <em>image from [mailto:s.weider@ucl.ac.uk Weider and colleagues]; Icarus (2010)</em><br /> | ||
<br /> | <br /> | ||
| − | Spectral data can distinguish compositionally different lava flows. In a just published paper, Shoshana Weider, Ian Crawford and Katherine Joy have used | + | Spectral data can distinguish compositionally different lava flows. In a just published paper, Shoshana Weider, Ian Crawford and Katherine Joy have used |
| − | this fact to estimate the thickness of lava flows in Mare Serenitatis. The panels above indicate the steps in their analysis. They start with maps of | + | this fact to estimate the thickness of lava flows in Mare Serenitatis. The panels above indicate the steps in their analysis. They start with maps of |
| − | compositionally different mare units (left) made by Harry Hiesinger et al. in 2000. The next step was to use existing procedures to convert UV-Vis | + | compositionally different mare units (left) made by Harry Hiesinger et al. in 2000. The next step was to use existing procedures to convert UV-Vis |
| − | Clementine multi-spectral data to estimate FeO (2nd) and TiO2 (3rd image) contents across the area of interest. Weider's team determined the FeO and | + | Clementine multi-spectral data to estimate FeO (2nd) and TiO2 (3rd image) contents across the area of interest. Weider's team determined the FeO and |
| − | TiO2 concentrations immediately around small craters (circles), as samples of the material the crater excavated as continuous ejecta, and they also | + | TiO2 concentrations immediately around small craters (circles), as samples of the material the crater excavated as continuous ejecta, and they also |
| − | determined compositions for each mare unit in the spaces between craters. The 4th panel shows with different colors the separate lava flows, and the | + | determined compositions for each mare unit in the spaces between craters. The 4th panel shows with different colors the separate lava flows, and the |
| − | circles representing craters show the color of the lava flows in each craters ejecta. For example, the purple unit (S28) includes two conspicuous craters | + | circles representing craters show the color of the lava flows in each craters ejecta. For example, the purple unit (S28) includes two conspicuous craters |
| − | that excavated thru the purple lavas and brought up material from the orange unit (S22) which must underly it. Based upon known relationships between | + | that excavated thru the purple lavas and brought up material from the orange unit (S22) which must underly it. Based upon known relationships between |
| − | depths and diameters for small craters, the next step was to estimate the likely thickness of each mare unit or lava flow (5th panel). The rightmost panel | + | depths and diameters for small craters, the next step was to estimate the likely thickness of each mare unit or lava flow (5th panel). The rightmost panel |
| − | shows the averaged estimates of lava flow thicknesses, which are in the range of 80 to 600 m, with the majority in Serenitatis being less than 150 m. The | + | shows the averaged estimates of lava flow thicknesses, which are in the range of 80 to 600 m, with the majority in Serenitatis being less than 150 m. The |
| − | authors list various uncertainties, but their estimates are consistent with others. They are however, much thicker than individual basaltic lava flows on Earth | + | authors list various uncertainties, but their estimates are consistent with others. They are however, much thicker than individual basaltic lava flows on Earth |
| − | and probably represent multiple flows of similar composition that have piled up on each other. This technique can now be done with higher precision using | + | and probably represent multiple flows of similar composition that have piled up on each other. This technique can now be done with higher precision using |
| − | the newly released Moon Mapper which has much higher spectral resolution than Clementine. This is another project that advanced amateurs can now | + | the newly released Moon Mapper which has much higher spectral resolution than Clementine. This is another project that advanced amateurs can now |
| − | accomplish. | + | accomplish. |
<br /> | <br /> | ||
<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br /> | <em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br /> | ||
| Line 26: | Line 26: | ||
<br /> | <br /> | ||
<strong>Related Links</strong><br /> | <strong>Related Links</strong><br /> | ||
| − | Rükl plate [ | + | Rükl plate [https://the-moon.us/wiki/R%C3%BCkl_24 24]<br /> |
Weider, Crawford and Joy (2010) Individual lava flow thicknesses in Oceanus Procellarum and Mare Serenitatis determined from Clementine multispectral <br /> | Weider, Crawford and Joy (2010) Individual lava flow thicknesses in Oceanus Procellarum and Mare Serenitatis determined from Clementine multispectral <br /> | ||
data. [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-505NS7W-1&_user=10&_coverDate=10%2F31%2F2010&_rdoc=6&_fmt=high&_orig=browse&_origin=browse&_zone=rslt_list_item&_srch=doc-info(%23toc%236821%232010%23997909997%232347754%23FLA%23display%23Volume)&_cdi=6821&_sort=d&_docanchor=&_ct=55&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=2ebf36be0b13058415755ad1decbbe68&searchtype=a Icarus 209 (2010) 323–336.]<br /> | data. [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-505NS7W-1&_user=10&_coverDate=10%2F31%2F2010&_rdoc=6&_fmt=high&_orig=browse&_origin=browse&_zone=rslt_list_item&_srch=doc-info(%23toc%236821%232010%23997909997%232347754%23FLA%23display%23Volume)&_cdi=6821&_sort=d&_docanchor=&_ct=55&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=2ebf36be0b13058415755ad1decbbe68&searchtype=a Icarus 209 (2010) 323–336.]<br /> | ||
Related [http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1300.pdf paper]<br /> | Related [http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1300.pdf paper]<br /> | ||
<br /> | <br /> | ||
| + | <hr /> | ||
<p><b>Yesterday's LPOD:</b> [[September 12, 2010|Happy 2500th]] </p> | <p><b>Yesterday's LPOD:</b> [[September 12, 2010|Happy 2500th]] </p> | ||
<p><b>Tomorrow's LPOD:</b> [[September 14, 2010|Seeing More At Wargentin]] </p> | <p><b>Tomorrow's LPOD:</b> [[September 14, 2010|Seeing More At Wargentin]] </p> | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
<!-- End of content --> | <!-- End of content --> | ||
{{wiki/ArticleFooter}} | {{wiki/ArticleFooter}} | ||
Latest revision as of 18:56, 13 October 2018
Ejecta Mapping > Lava Depths
image from Weider and colleagues; Icarus (2010)
Spectral data can distinguish compositionally different lava flows. In a just published paper, Shoshana Weider, Ian Crawford and Katherine Joy have used
this fact to estimate the thickness of lava flows in Mare Serenitatis. The panels above indicate the steps in their analysis. They start with maps of
compositionally different mare units (left) made by Harry Hiesinger et al. in 2000. The next step was to use existing procedures to convert UV-Vis
Clementine multi-spectral data to estimate FeO (2nd) and TiO2 (3rd image) contents across the area of interest. Weider's team determined the FeO and
TiO2 concentrations immediately around small craters (circles), as samples of the material the crater excavated as continuous ejecta, and they also
determined compositions for each mare unit in the spaces between craters. The 4th panel shows with different colors the separate lava flows, and the
circles representing craters show the color of the lava flows in each craters ejecta. For example, the purple unit (S28) includes two conspicuous craters
that excavated thru the purple lavas and brought up material from the orange unit (S22) which must underly it. Based upon known relationships between
depths and diameters for small craters, the next step was to estimate the likely thickness of each mare unit or lava flow (5th panel). The rightmost panel
shows the averaged estimates of lava flow thicknesses, which are in the range of 80 to 600 m, with the majority in Serenitatis being less than 150 m. The
authors list various uncertainties, but their estimates are consistent with others. They are however, much thicker than individual basaltic lava flows on Earth
and probably represent multiple flows of similar composition that have piled up on each other. This technique can now be done with higher precision using
the newly released Moon Mapper which has much higher spectral resolution than Clementine. This is another project that advanced amateurs can now
accomplish.
Chuck Wood
Technical Details
Related Links
Rükl plate 24
Weider, Crawford and Joy (2010) Individual lava flow thicknesses in Oceanus Procellarum and Mare Serenitatis determined from Clementine multispectral
data. Icarus 209 (2010) 323–336.
Related paper
Yesterday's LPOD: Happy 2500th
Tomorrow's LPOD: Seeing More At Wargentin
COMMENTS?
Register, Log in, and join in the comments.
