Re: [Utah-astronomy] More on Upheaval Dome
Jim Gibson wrote:
I felt somewhat like you expressed about central peaks. When I read the comment about central peaks requiring a certain force I looked around on the moon and was surprised how many small creators didn’t have central peaks. There are also a lot of big creators with out central peaks either. So, I am still not satisfied that I know enough.
(In reply to Jim and other miscellaneous topics in this thread:) There is pattern to the size and morphology of lunar craters - and to craters on all the other rocky planets. It begins with small bowl shaped craters, then central peaks form, then the central peaks disappear and a single outer ring of peaks develops. Finally, with big basins like Mare Orientale, multiple ring peaks form at distances from the center of the impact at a ratio of 1 to the square root of 2. This is a link to a wikispace page that I put together a few months ago that shows on one side, an animated main lunar crater sequence. On the other is high-motion photography of a water droplet from a YouTube source. http://canopus56.wikispaces.com/MainLunarSequence The morphology sequence of lunar crater formation is listed in the text paragraph beneath the two animations. Formation of a crater central peak is gravity dependent. The Moon has one-sixth the gravity field of the Earth. On the Moon, central peaks begin to be expressed when a crater reaches about 17 to 20 km in diameter. The Earth has a higher gravity field, so central peaks begin to become expressed at around 6km. What you see at Upheaval is the eroded remanents of an about 8km dia crater that formed 170 million years ago. The original crater was one or two kilometers deep. Most of what remains is the bottom 1/5 of the impact crater. It is not a clear matter. You may be seeing either (a) the floor of the original crater or (b) the petrified impact shock waves in the rock just beneath the floor of the original crater. Craters are scaled dependent on the gravity field of the planet they form on. That just makes Upheaval more cool. It's like looking at a dissection of what is at or underneath all those 17-25km craters that you have looked at on the Moon. See Fig. 4 in Huntoon (2000), Utah Geo. Assoc. Pub. 28:619-628 for a diagram showing what the original crater looked like. url: http://www.utahgeology.org/pub28_pdf_files/UpheavalDome.pdf. See Pike 1979 re: gravity dependent of effects on crater morphology that is seen on all solar system planets from Mercury, Earth, the Moon and Mars. Pike, R.J. 1979. Simple to complex craters: transition on the Moon. LPI Sci. Conf. VII:700-702. url: http://adsabs.harvard.edu/abs/1976LPI.....7..700P Here's picture of a 4km impact basin at the village of Steinheim, Germany. It's only a few million years old and is still filled in. It's probably similar to what Upheaval looked like 170 million years ago. http://www.astro.hr/vsa97/eng/html/ries_crater.html Another possible "what it originally looked like 170 million years ago" analogy is the 2.5 km Roter Kamm Crater in Nambia. http://www.lpi.usra.edu/publications/slidesets/craters/slide_14.html Shoemaker didn't find multiplanar PDFs at Upheaval. In the 1980s he found "shatter cones" a.k.a shock cones, a feature that can created by either volcanic explosions or meteorites, although shatter cones are more typically associated with meteor impact sites. There are two pictures of fully formed shatter cones from a Canadian meteor impact site at this url: Shatter cones from Carswell Sudbury impact structures in Canada Right Carswell impact structure, Canada. url: http://www.unb.ca/passc/ImpactDatabase/essay.html#ident A picture of the specific shatter cone that Shoemaker found - actually the broken bottom half of a shatter cone - can be seen as Fig. 18 in Kriens, Shoemaker and Herkenhoff (1999). (You'll have to go to university library with access rights to the journal to access it.) Kriens, Shoemaker and Herkenhoff. 1999. Geology of the Upheaval Dome impact structure, southeast Utah J. of Geophys. Res. 104:(18)18867-18887 url: http://www.agu.org/journals/ABS/1999/1998JE000587.shtml There's a nice scientific historical arc to the Upheaval story. Shoemaker first became famous as the co-author of a paper in the late 50s or early 60s that examined the technique for confirming impact craters by their shock wave characteristics. One of the studies sites in his early paper was the possible binary asteriod impact at Nördlingen Ries (24km) and Steinheim (4km), in Bavaria, Germany. As a result of Shoemaker's work, the German's created an institute that stores core samples taken from all around the Nördlingen Ries area. Kenkmann, who did find the multiplanar PDF crystals at Upheaval, is a Humboldt Univ. of Berlin mineralology professor who also happens to be a chair at - I think I translated this nearly right - the Center for Meteor Impact Studies at Nördlingen - a joint project of the Humboldt Univ. of Berlin and the City of Nordlingen. ZERIN (Zentrum für Rieskrater- und Impaktforschung Nördlingen) http://www.museum.hu-berlin.de/min/zerin/zerin.html Shoemaker characterizes Nordlingen Ries and Steinheim as a meteor impact sites. German boy grows up to become a minerology professer. Forty years later he flys back to Utah to return the favor. Or at least that's how I read the sequence of events. -:) Clear Skies - Kurt
Kurt, Really good post. I am saving this one. Thanks jg --- On Wed, 1/28/09, Canopus56 <canopus56@yahoo.com> wrote: From: Canopus56 <canopus56@yahoo.com> Subject: Re: [Utah-astronomy] More on Upheaval Dome To: "Utah Astronomy List Serv" <utah-astronomy@mailman.xmission.com> Date: Wednesday, January 28, 2009, 6:27 PM Jim Gibson wrote:
I felt somewhat like you expressed about central peaks. When I read the comment about central peaks requiring a certain force I looked around on the moon and was surprised how many small creators didn’t have central peaks. There are also a lot of big creators with out central peaks either. So, I am still not satisfied that I know enough.
(In reply to Jim and other miscellaneous topics in this thread:) There is pattern to the size and morphology of lunar craters - and to craters on all the other rocky planets. It begins with small bowl shaped craters, then central peaks form, then the central peaks disappear and a single outer ring of peaks develops. Finally, with big basins like Mare Orientale, multiple ring peaks form at distances from the center of the impact at a ratio of 1 to the square root of 2. This is a link to a wikispace page that I put together a few months ago that shows on one side, an animated main lunar crater sequence. On the other is high-motion photography of a water droplet from a YouTube source. http://canopus56.wikispaces.com/MainLunarSequence The morphology sequence of lunar crater formation is listed in the text paragraph beneath the two animations. Formation of a crater central peak is gravity dependent. The Moon has one-sixth the gravity field of the Earth. On the Moon, central peaks begin to be expressed when a crater reaches about 17 to 20 km in diameter. The Earth has a higher gravity field, so central peaks begin to become expressed at around 6km. What you see at Upheaval is the eroded remanents of an about 8km dia crater that formed 170 million years ago. The original crater was one or two kilometers deep. Most of what remains is the bottom 1/5 of the impact crater. It is not a clear matter. You may be seeing either (a) the floor of the original crater or (b) the petrified impact shock waves in the rock just beneath the floor of the original crater. Craters are scaled dependent on the gravity field of the planet they form on. That just makes Upheaval more cool. It's like looking at a dissection of what is at or underneath all those 17-25km craters that you have looked at on the Moon. See Fig. 4 in Huntoon (2000), Utah Geo. Assoc. Pub. 28:619-628 for a diagram showing what the original crater looked like. url: http://www.utahgeology.org/pub28_pdf_files/UpheavalDome.pdf. See Pike 1979 re: gravity dependent of effects on crater morphology that is seen on all solar system planets from Mercury, Earth, the Moon and Mars. Pike, R.J. 1979. Simple to complex craters: transition on the Moon. LPI Sci. Conf. VII:700-702. url: http://adsabs.harvard.edu/abs/1976LPI.....7..700P Here's picture of a 4km impact basin at the village of Steinheim, Germany. It's only a few million years old and is still filled in. It's probably similar to what Upheaval looked like 170 million years ago. http://www.astro.hr/vsa97/eng/html/ries_crater.html Another possible "what it originally looked like 170 million years ago" analogy is the 2.5 km Roter Kamm Crater in Nambia. http://www.lpi.usra.edu/publications/slidesets/craters/slide_14.html Shoemaker didn't find multiplanar PDFs at Upheaval. In the 1980s he found "shatter cones" a.k.a shock cones, a feature that can created by either volcanic explosions or meteorites, although shatter cones are more typically associated with meteor impact sites. There are two pictures of fully formed shatter cones from a Canadian meteor impact site at this url: Shatter cones from Carswell Sudbury impact structures in Canada Right Carswell impact structure, Canada. url: http://www.unb.ca/passc/ImpactDatabase/essay.html#ident A picture of the specific shatter cone that Shoemaker found - actually the broken bottom half of a shatter cone - can be seen as Fig. 18 in Kriens, Shoemaker and Herkenhoff (1999). (You'll have to go to university library with access rights to the journal to access it.) Kriens, Shoemaker and Herkenhoff. 1999. Geology of the Upheaval Dome impact structure, southeast Utah J. of Geophys. Res. 104:(18)18867-18887 url: http://www.agu.org/journals/ABS/1999/1998JE000587.shtml There's a nice scientific historical arc to the Upheaval story. Shoemaker first became famous as the co-author of a paper in the late 50s or early 60s that examined the technique for confirming impact craters by their shock wave characteristics. One of the studies sites in his early paper was the possible binary asteriod impact at Nördlingen Ries (24km) and Steinheim (4km), in Bavaria, Germany. As a result of Shoemaker's work, the German's created an institute that stores core samples taken from all around the Nördlingen Ries area. Kenkmann, who did find the multiplanar PDF crystals at Upheaval, is a Humboldt Univ. of Berlin mineralology professor who also happens to be a chair at - I think I translated this nearly right - the Center for Meteor Impact Studies at Nördlingen - a joint project of the Humboldt Univ. of Berlin and the City of Nordlingen. ZERIN (Zentrum für Rieskrater- und Impaktforschung Nördlingen) http://www.museum.hu-berlin.de/min/zerin/zerin.html Shoemaker characterizes Nordlingen Ries and Steinheim as a meteor impact sites. German boy grows up to become a minerology professer. Forty years later he flys back to Utah to return the favor. Or at least that's how I read the sequence of events. -:) Clear Skies - Kurt _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com
Well, I'm obviously way out of my league here, at least scientifically and technically speaking, but thanks all for sharing your knowledge, esp. Kurt and Rodger. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Canopus56 Sent: Wednesday, January 28, 2009 6:27 PM To: Utah Astronomy List Serv Subject: Re: [Utah-astronomy] More on Upheaval Dome Jim Gibson wrote:
I felt somewhat like you expressed about central peaks. When I read the comment about central peaks requiring a certain force I looked around on the moon
and was surprised how many small creators didnt have central peaks. There are also a lot of big creators with out central peaks either. So, I am still not satisfied that I know enough.
(In reply to Jim and other miscellaneous topics in this thread:) There is pattern to the size and morphology of lunar craters - and to craters on all the other rocky planets. It begins with small bowl shaped craters, then central peaks form, then the central peaks disappear and a single outer ring of peaks develops. Finally, with big basins like Mare Orientale, multiple ring peaks form at distances from the center of the impact at a ratio of 1 to the square root of 2. This is a link to a wikispace page that I put together a few months ago that shows on one side, an animated main lunar crater sequence. On the other is high-motion photography of a water droplet from a YouTube source. http://canopus56.wikispaces.com/MainLunarSequence The morphology sequence of lunar crater formation is listed in the text paragraph beneath the two animations. Formation of a crater central peak is gravity dependent. The Moon has one-sixth the gravity field of the Earth. On the Moon, central peaks begin to be expressed when a crater reaches about 17 to 20 km in diameter. The Earth has a higher gravity field, so central peaks begin to become expressed at around 6km. What you see at Upheaval is the eroded remanents of an about 8km dia crater that formed 170 million years ago. The original crater was one or two kilometers deep. Most of what remains is the bottom 1/5 of the impact crater. It is not a clear matter. You may be seeing either (a) the floor of the original crater or (b) the petrified impact shock waves in the rock just beneath the floor of the original crater. Craters are scaled dependent on the gravity field of the planet they form on. That just makes Upheaval more cool. It's like looking at a dissection of what is at or underneath all those 17-25km craters that you have looked at on the Moon. See Fig. 4 in Huntoon (2000), Utah Geo. Assoc. Pub. 28:619-628 for a diagram showing what the original crater looked like. url: http://www.utahgeology.org/pub28_pdf_files/UpheavalDome.pdf. See Pike 1979 re: gravity dependent of effects on crater morphology that is seen on all solar system planets from Mercury, Earth, the Moon and Mars. Pike, R.J. 1979. Simple to complex craters: transition on the Moon. LPI Sci. Conf. VII:700-702. url: http://adsabs.harvard.edu/abs/1976LPI.....7..700P Here's picture of a 4km impact basin at the village of Steinheim, Germany. It's only a few million years old and is still filled in. It's probably similar to what Upheaval looked like 170 million years ago. http://www.astro.hr/vsa97/eng/html/ries_crater.html Another possible "what it originally looked like 170 million years ago" analogy is the 2.5 km Roter Kamm Crater in Nambia. http://www.lpi.usra.edu/publications/slidesets/craters/slide_14.html Shoemaker didn't find multiplanar PDFs at Upheaval. In the 1980s he found "shatter cones" a.k.a shock cones, a feature that can created by either volcanic explosions or meteorites, although shatter cones are more typically associated with meteor impact sites. There are two pictures of fully formed shatter cones from a Canadian meteor impact site at this url: Shatter cones from Carswell Sudbury impact structures in Canada Right Carswell impact structure, Canada. url: http://www.unb.ca/passc/ImpactDatabase/essay.html#ident A picture of the specific shatter cone that Shoemaker found - actually the broken bottom half of a shatter cone - can be seen as Fig. 18 in Kriens, Shoemaker and Herkenhoff (1999). (You'll have to go to university library with access rights to the journal to access it.) Kriens, Shoemaker and Herkenhoff. 1999. Geology of the Upheaval Dome impact structure, southeast Utah J. of Geophys. Res. 104:(18)18867-18887 url: http://www.agu.org/journals/ABS/1999/1998JE000587.shtml There's a nice scientific historical arc to the Upheaval story. Shoemaker first became famous as the co-author of a paper in the late 50s or early 60s that examined the technique for confirming impact craters by their shock wave characteristics. One of the studies sites in his early paper was the possible binary asteriod impact at Nördlingen Ries (24km) and Steinheim (4km), in Bavaria, Germany. As a result of Shoemaker's work, the German's created an institute that stores core samples taken from all around the Nördlingen Ries area. Kenkmann, who did find the multiplanar PDF crystals at Upheaval, is a Humboldt Univ. of Berlin mineralology professor who also happens to be a chair at - I think I translated this nearly right - the Center for Meteor Impact Studies at Nördlingen - a joint project of the Humboldt Univ. of Berlin and the City of Nordlingen. ZERIN (Zentrum für Rieskrater- und Impaktforschung Nördlingen) http://www.museum.hu-berlin.de/min/zerin/zerin.html Shoemaker characterizes Nordlingen Ries and Steinheim as a meteor impact sites. German boy grows up to become a minerology professer. Forty years later he flys back to Utah to return the favor. Or at least that's how I read the sequence of events. -:) Clear Skies - Kurt _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com No virus found in this incoming message. Checked by AVG. Version: 7.5.552 / Virus Database: 270.10.15/1921 - Release Date: 1/28/2009 6:37 AM No virus found in this outgoing message. Checked by AVG. Version: 7.5.552 / Virus Database: 270.10.15/1921 - Release Date: 1/28/2009 6:37 AM
It's been decades, but I seem to remember Carl Sagan noting this in an episode of "Cosmos". Also Shoemaker himself in a more recent documentary on public TV; the title escapes me. Something to do with earth-grazing asteroids, IIRC.. On Wed, Jan 28, 2009 at 6:27 PM, Canopus56 <canopus56@yahoo.com> wrote:
Shoemaker characterizes Nordlingen Ries and Steinheim as a meteor impact sites.
participants (4)
-
Canopus56 -
Chuck Hards -
Jim Gibson -
Kim