geophysics - BLOGS - Blacksciencefictionsociety2024-03-29T06:17:34Zhttps://blacksciencefictionsociety.com/profiles/blogs/feed/tag/geophysicsOur Shrinking Moon...https://blacksciencefictionsociety.com/profiles/blogs/our-shrinking-moon2019-05-20T10:00:00.000Z2019-05-20T10:00:00.000ZReginald L. Goodwinhttps://blacksciencefictionsociety.com/members/ReginaldLGoodwin<div><table class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;" cellspacing="0" align="center"><tbody><tr><td style="text-align: center;"><a rel="nofollow" style="margin-left: auto; margin-right: auto;" href="https://3.bp.blogspot.com/-jwa10dIQ-Y4/XOIj_xzzzpI/AAAAAAAAOR4/ftm-x78tFHQCokLhKyegfoghNbMo5FhagCLcBGAs/s1600/RQvxr94CFYM2KM.jpg"><img src="https://3.bp.blogspot.com/-jwa10dIQ-Y4/XOIj_xzzzpI/AAAAAAAAOR4/ftm-x78tFHQCokLhKyegfoghNbMo5FhagCLcBGAs/s400/RQvxr94CFYM2KM.jpg" width="400" height="400" border="0"/></a></td></tr><tr><td class="tr-caption" style="text-align: center;">New surface features of the Moon have been discovered in a region called Mare Frigoris, outlined here in teal. NASA<br/>Image: <a href="http://va.newsrepublic.net/s/vMYNUS" target="_blank" rel="noopener">New Republic</a></td></tr></tbody></table><p> </p><p><span style="font-family: Georgia, Times New Roman, serif;">Topics: Astrophysics, Geophysics, Moon, NASA, Planetary Science</span></p><div style="text-align: justify;"><br/><span style="font-family: Georgia, Times New Roman, serif;">The Moon is <a href="https://www.nasa.gov/mission_pages/LRO/news/shrinking-moon.html" target="_blank" rel="noopener">shrinking</a> as its interior cools, getting more than about 150 feet <a href="https://physics4thecool.blogspot.com/2019/05/our-shrinking-moon.html" target="_blank" rel="noopener">(50 meters) skinnier</a> over the last several hundred million years. Just as a grape wrinkles as it shrinks down to a raisin, the Moon gets wrinkles as it shrinks. Unlike the flexible skin on a grape, the Moon’s surface crust is brittle, so it breaks as the Moon shrinks, forming “thrust faults” where one section of crust is pushed up over a neighboring part.</span></div><div style="text-align: justify;"><br/><span style="font-family: Georgia, Times New Roman, serif;">“Our analysis gives the first evidence that these faults are still active and likely producing moonquakes today as the Moon continues to gradually cool and shrink,” said Thomas Watters, senior scientist in the Center for Earth and Planetary Studies at the Smithsonian’s National Air and Space Museum in Washington. “Some of these quakes can be fairly strong, around five on the Richter scale.”</span></div><div style="text-align: justify;"><br/><span style="font-family: Georgia, Times New Roman, serif;">Watters is lead author of a study that analyzed data from four seismometers placed on the Moon by the Apollo astronauts using an algorithm, or mathematical program, developed to pinpoint quake locations detected by a sparse seismic network. The algorithm gave a better estimate of moonquake locations. Seismometers are instruments that measure the shaking produced by quakes, recording the arrival time and strength of various quake waves to get a location estimate, called an epicenter. The study was <a href="https://www.nature.com/articles/s41561-019-0362-2" target="_blank" rel="noopener">published May 13 in Nature Geoscience</a>.</span></div><p><br/><a href="https://www.nasa.gov/press-release/goddard/2019/moonquakes" target="_blank" rel="noopener"><br/></a> <span style="font-family: Georgia, Times New Roman, serif;"><a href="https://www.nasa.gov/press-release/goddard/2019/moonquakes" target="_blank" rel="noopener">Shrinking Moon May Be Generating Moonquakes</a>, NASA</span></p></div>Mars Quake...https://blacksciencefictionsociety.com/profiles/blogs/mars-quake2019-05-09T10:00:00.000Z2019-05-09T10:00:00.000ZReginald L. Goodwinhttps://blacksciencefictionsociety.com/members/ReginaldLGoodwin<div><table class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;" cellspacing="0" align="center"><tbody><tr><td style="text-align: center;"><a rel="nofollow" style="margin-left: auto; margin-right: auto;" href="https://1.bp.blogspot.com/-5g2w_swVmQA/XNOZnuuQOAI/AAAAAAAAORQ/wWSfHRnir3MJg3VW8nuQRsbfvQQaASg-wCLcBGAs/s1600/Mars%2BQuake.PNG"><img src="https://1.bp.blogspot.com/-5g2w_swVmQA/XNOZnuuQOAI/AAAAAAAAORQ/wWSfHRnir3MJg3VW8nuQRsbfvQQaASg-wCLcBGAs/s400/Mars%2BQuake.PNG" width="400" height="221" border="0"/></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Model of the spaceship Insight, NASA's first robotic lander, dedicated to study the deep interior of Mars. REUTERS/Mike Blake/File Photo</td></tr></tbody></table><p> </p><p><span style="font-family: Georgia, Times New Roman, serif;">Topics: Geophysics, Mars, NASA, Planetary Exploration</span></p><div style="text-align: justify;"><br/><span style="font-family: Georgia, Times New Roman, serif;">Finals are over. I'll be with our new granddaughter and her parents next week, along with working on my thesis, following up on my PhD application and changing diapers. My posts will be sporadic since I'll be on the road. I'll catch up.</span></div><div style="text-align: justify;"><br/><em><span style="font-family: Georgia, Times New Roman, serif;">The breakthrough came nearly <a href="https://physics4thecool.blogspot.com/2019/05/mars-quake.html" target="_blank" rel="noopener">five months after InSight</a>, the first spacecraft designed specifically to study the deep interior of a distant world, touched down on the surface of Mars to begin its two-year seismological mission on the red planet.</span></em></div><div style="text-align: justify;"><br/><em><span style="font-family: Georgia, Times New Roman, serif;">The faint rumble characterized by JPL scientists as a likely marsquake, roughly equal to a 2.5 magnitude earthquake, was recorded on April 6 - the lander’s 128th Martian day, or sol.</span></em></div><div style="text-align: justify;"><br/><em><span style="font-family: Georgia, Times New Roman, serif;">It was detected by InSight’s French-built seismometer, an instrument sensitive enough to measure a seismic wave just one-half the radius of a hydrogen atom.</span></em></div><div style="text-align: justify;"><br/><em><span style="font-family: Georgia, Times New Roman, serif;">The lunar and Martian surfaces are extremely quiet compared with Earth, which experiences constant low-level seismic noise from oceans and weather as well as quakes that occur along subterranean fault lines created by shifting tectonic plates in the planet’s crust.</span></em></div><div style="text-align: justify;"><br/><em><span style="font-family: Georgia, Times New Roman, serif;">Mars and the moon lack tectonic plates. Their seismic activity is instead driven by a cooling and contracting process that causes stress to build up and become strong enough to rupture the crust.</span></em></div><div style="text-align: justify;"><br/><em><span style="font-family: Georgia, Times New Roman, serif;">Three other apparent seismic signals were picked up by InSight on March 14, April 10 and April 11 but were even smaller and more ambiguous in origin, leaving scientists less certain they were actual marsquakes.</span></em></div><p> </p><p><a href="https://www.reuters.com/article/us-space-exploration-mars/nasa-probe-detects-likely-marsquake-an-interplanetary-first-idUSKCN1RZ2BY" target="_blank" rel="noopener"><span style="font-family: Georgia, Times New Roman, serif;">NASA probe detects likely 'marsquake' - an interplanetary first</span></a><br/><span style="font-family: Georgia, Times New Roman, serif;">Joey Roulette, Reuters Science</span></p></div>