atlanta geological society newsletteratlantageologicalsociety.org/wp...13ags_newsletter...jun 10,...
TRANSCRIPT
OCTOBER MEETING
Join us Tuesday, October 29, 2013 at the Fernbank Museum of Natural History, 760 Clifton Road NE, Atlanta GA. The meeting social starts at 6:30 pm. This month our speaker will be our own Cassidy Sutherland. She will be speaking on Geographical Information Systems (GIS) and Geoscience Applications. As a bit of biographical information, Cassidy graduated from Georgia State University in 2008 with my BS in Geology and have been working as a geologist for Golder Associates since October 2008. She has served as AGS’ vice president since 2009. Her non-work hours are spent swimming, biking and running distances that make people (including her) question her sanity. Please come and enjoy the social time and the interesting presentation on Tuesday, October 29, 2013.
Next meeting of the Atlanta Geological Society is October 29, 2013
Fernbank Museum of Natural History (Clifton Road) Social begins at 6:30 pm – Meeting begins at 7:00 pm
OCTOBER 2013
Atlanta Geological Society Newsletter
ODDS AND ENDS Ben Bentkowski, Newsletter Editor I’m not sure how many of you noted the magnitude 7.7 earthquake that occurred offshore from Pakistan but I thought it was most unusual that it created a new island. Ben B, Newsletter Editor Rising 18 meters above the sea and 76 meters along the long axis it is not a large island. Also, as you can see in the photo, the surface is covered in broken rocks. Probably comes along with being thrust from the ocean by a big earthquake. But there it is, new land. I think the most unusual characteristic about this island is the speed at which it was created. So much of geology moves at such an exceedingly slow pace. The tectonic plates move at the approximate speed of fingernails growing! Links back to the literally groundbreaking work by Mathews and Vine first describing sea floor spreading fifty years ago, which is covered in this issue as well. Also, please note the publication of most of the 2014 meeting dates. I’ll work in the PG study class dates as they get closer. B. B.
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What Direction Does Earth's Center Spin? New Insights Solve 300-Year-Old Problem Sep. 16, 2013 — Scientists at the University of Leeds have solved a 300-year-old riddle about which direction the center of Earth spins.
Earth's inner core, made up of solid iron, 'superrotates' in an eastward direction -- meaning it spins faster than the rest of the planet -- while the outer core, comprising mainly molten iron, spins westwards at a slower pace. Although Edmund Halley -- who also discovered the famous comet -- showed the westward-drifting motion of Earth's geomagnetic field in 1692, it is the first time that scientists have been able to link the way the inner core spins to the behavior of the outer core. The planet behaves in this way because it is responding to Earth's geomagnetic field. The findings, published in Proceedings of the National Academy of Sciences, help scientists to interpret the dynamics of the core of Earth, the source of our planet's magnetic field. In the last few decades, seismometers measuring earthquakes travelling through Earth's core have identified an eastwards, or superrotation of the solid inner core, relative to Earth's surface. "The link is simply explained in terms of equal and opposite action," explains Dr Philip Livermore, of the School of Earth and Environment at the University of Leeds. "The magnetic field pushes eastwards on the inner core, causing it to spin faster than the Earth, but it also pushes in the opposite direction in the liquid outer core, which creates a westward motion." The solid iron inner core is about the size of the Moon. It is surrounded by the liquid outer core, an iron alloy, whose convection-driven movement generates the geomagnetic field. The fact that Earth's internal magnetic field changes slowly, over a timescale of decades, means that the electromagnetic force responsible for pushing the inner and outer cores will itself change over time. This may explain fluctuations in the predominantly eastwards rotation of the inner core, a phenomenon reported for the last 50 years by Tkalčić et al. in a recent study published in Nature Geoscience. Other previous research based on archeological artifacts and rocks, with ages of hundreds to thousands of years, suggests that the drift direction has not always been westwards: some periods of eastwards motion may have occurred in the last 3,000 years. Viewed within the conclusions of the new model, this suggests that the inner core may have undergone a westwards rotation in such periods. The authors used a model of Earth's core which was run on the giant super-computer Monte Rosa, part of the Swiss National Supercomputing Centre in Lugano, Switzerland. Using a new method, they were able to simulate Earth's core with accuracy about 100 times better than other models. The study was a collaboration between the University of Leeds and the Swiss Federal Institute of Technology, Zurich. University of Leeds (2013, September 16). What direction does Earth's center spin? New insights solve 300-year-old problem. ScienceDaily. Retrieved September 18, 2013, from http://www.sciencedaily.com/releases/2013/09/130916162005.htm
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http://icaci.org/map-of-the-month/
The International Cartographic Accociation
First off, the scale of this newsletter does not do this map justice. As you can see, there has been quite a jumble of tectonic activity as evidenced by all the various formations seen in the Pyranees Mountains. Also evidenced on this reduced scale are the rivers running to the north and south out of the highlands. This organization has a map of the month andf I highly recommend that you follow the link and check out the other maps. They are not all geological but we all have an appreciation of cartography. By viewing the maps of the month, they all have links back to the organization that produced the winning map of the month. Could be any number of hours of interesting maps and ideas down those internet trails, paths one might not usually take.
Later in the newsletter, please find a map of the world’s magnetic anomalies.
B.B.
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BOOK REVIEW
by
Jacq Marie Jack
Authors and fellow members of the Atlanta Geological Society, Pamela J. W. Gore and William Witherspoon take the reader on the ultimate road trip in their book, Roadside Geology of Georgia (available at Amazon.com and Barnes and Noble.com.) This book is an outstanding addition to the current series of Roadside Geology Guides of the United States published by Mountain Press Publishing. This Roadside Guide offers the reader a ticket to the world of geological wonders found here in Georgia. It beckons the reader to plan That Trip, to take to the road and experience firsthand our state’s natural treasures.
Beginning with an overview discussion of the general geology of Georgia, the authors introduce the reader to geological principals to ensure an easy understanding of the specific regional geology discussions that follow. The book guides the reader through the sedimentary sequences of the Barrier Islands and the Georgia Coastal Plain, Valley and Ridge, and Appalachian Plateau before ending the state’s tour in the metamorphic and igneous complexes Piedmont and Blue Ridge. The authors expertly illustrate their narrative of each geological region with informative color photographs, charts, graphs, maps and a glossary of terms. Included in the discussion are sidebars tying Georgia’s unique Geology to regional culture and history. Following each regional discussion, the authors include a detailed road log describing the roadside geology. The book also includes an appendix of Georgia museums and exhibits featuring objects of geologic interest.
This book is a “must have” for every Georgia field geologist and a ready reference for the office geologist. More importantly because of the clarity of the writing and visual aids, this book will make an excellent gift for students, amateur scientists and outdoor enthusiasts. My suggestion? Buy three copies: one for the office, one for the field truck and one to give away to a friend with an interest in geology.
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Scenic Saturday: our stripy oceans, explained 50 years ago! Posted on September 7, 2013 by Chris Rowan
A slightly different Scenic Saturday this weekend, as we celebrate an important milestone in geological science: a look at the South Pacific through a geophysical lens. The colours on this map show fluctuations in the Earth’s magnetic field produced by strongly magnetised bits of the Earth’s crust: reds and purples show where the crust is magnetised in the same direction as the current magnetic field, and give it a bit of a boost: blues show where it is magnetised in the opposite direction, and cancel some of it out. You can’t miss that when viewed through magnetic eyes, the Earth’s ocean basins are distinctly stripy. When geophysicists first started mapping the seafloor in earnest with sonar and magnetometers in the 1950s, the only thing more surprising than the discovery of a 60,000 km linear chain of mountains running through the middle of most oceans was the long linear areas of positively and negatively magnetised crust that paralleled the trend of these mid-ocean ridges. But 50 years ago today, a paper was published in Nature that purported to explain this grand geophysical mystery. Fred Vine and Drummond Matthews thought through the consequences of the hypothesis put forward by Harry Hess, that new oceanic crust was being continuously produced by the eruption of basalt at mid-ocean ridges. When combined with the facts that newly cooled basalt has a strong remanent magnetisation aligned with the ambient magnetic field, and that the Earth’s magnetic field reverses its polarity every million years or so. Vine and Matthews* argued that if seafloor spreading was indeed occurring at mid-ocean ridges, then linear positive and negative magnetic anomalies, formed from crust produced in normal and reversed polarity chrons, would form a symmetric pattern around the mid-ocean ridges, which is exactly what we see. Despite some of the coverage in the past few days, the publication of the Vine and Matthews paper does not really mark the “birth of plate tectonics”. No scientific revolution really happens overnight; you will never see a scientific community collectively double-take and say, ‘Doh! That’s so obvious! Why didn’t I realise that before?!’. This is just one step on a journey that started before even Alfred Wegner’s theory of continental drift, and continued into at least the late 1960s, when the idea of rigid plates was formalised, and even the 1970s, when the wider geological community finally took notice of what those crazy marine geophysicists were up to. For the full story – told far better than I ever could – read this great piece by Naomi Oreskes. Nonetheless, publication of the Vine and Matthews paper was an important milestone in the development of plate tectonics, because it demonstrated how an observation that was very hard to explain without invoking plate tectonic processes became very easy to explain if you did; and it is that sort of achievement that makes other scientists start to take notice of an upstart new theory.
Magnetic anomalies in the South Pacific: part of the World Magnetic Anomaly Map, via a Useful KML file from San Diego State University
http://all-geo.org/highlyallochthonous/2013/09/scenic-saturday-our-stripy-oceans-explained-50-years-ago-today/
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BENEFITS OF AN AGS MEMBERSHIP • Location – AGS meets at the Fernbank Museum of Natural History,
which is a truly awesome facility central to most of our membership. • Cost – AGS membership ($25 general; $10 student) is the most
inexpensive for any geological society in the SE. • Active – AGS holds nine lectures a year and is one of the most active
geological societies in the SE. • AEG – For one of our lectures, AGS co-sponsors with the Association of
Environmental & Engineering Geologists to annually present the “Richard H. Jahns Distinguished Lecturer” while in Atlanta.
• PDH – AGS is recognized by Alabama, South Carolina, and other professional state boards to provide Professional Development Hours for our lectures, as well as field trips and workshops.
• PG Classes – AGS offers nearly monthly Professional Geologist development training classes in preparation for passing the ASBOG examinations and has been recognized by the Georgia State Geologist as enhancing PG test scores for participants.
• Free Food – AGS offers free pizza and Coke at all of our regular meetings, sandwiches and hors d’oeuvres at the Jahns lecture, and a sit-down BBQ dinner at our June social.
• IMAX – As part of the June social, AGS and Fernbank present a free IMAX movie.
• Networking – AGS meetings include professionals, academics, regulators, and others who all share the same interest in geological sciences.
• Resume – AGS membership and even involvement in one of our many committees will enhance any resume.
Annual membership dues for the Atlanta Geological Society are $25 for professional membership, $10 for students, and $100 for corporate sponsorship (which includes up to 4 professional memberships). Please complete the application form and submit with your payment to the AGS Treasurer. For further details about membership, please contact the AGS Membership Chairman – Ben Bentkowski
cell -770-296-2529 [email protected]
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Another of the maps from the International Cartographic Association. •
Sorry, I could not get it go to landscape…
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Birth of Earth's Continents: New Research Points to Crust Stacking, Rather Than Upwelling of Hot Material Sep. 16, 2013 — New research led by a University of Calgary geophysicist provides strong evidence against continent formation above a hot mantle plume, similar to an environment that presently exists beneath the Hawaiian Islands.
The analysis, published this month in Nature Geoscience, indicates that the nuclei of Earth's continents formed as a byproduct of mountain-building processes, by stacking up slabs of relatively cold oceanic crust. This process created thick, strong 'keels' in Earth's mantle that supported the overlying crust and enabled continents to form. The scientific clues leading to this conclusion derived from computer simulations of the slow cooling process of continents, combined with analysis of the distribution of diamonds in the deep Earth. The Department of Geoscience's Professor David Eaton developed computer software to enable numerical simulation of the slow diffusive cooling of Earth's mantle over a time span of billions of years. Working in collaboration with former graduate student, Assistant Professor Claire Perry from the Universite du Quebec a Montreal, Eaton relied on the geological record of diamonds found in Africa to validate his innovative computer simulations. "For the first time, we are able to quantify the thermal evolution of a realistic 3D Earth model spanning billions of years from the time continents were formed," states Perry. Mantle plumes consist of an upwelling of hot material within Earth's mantle. Plumes are thought to be the cause of some volcanic centres, especially those that form a linear volcanic chain like Hawaii. Diamonds, which are generally limited to the deepest and oldest parts of the continental mantle, provide a wealth of information on how the host mantle region may have formed. "Ancient mantle keels are relatively strong, cold and sometimes diamond-bearing material. They are known to extend to depths of 200 kilometres or more beneath the ancient core regions of continents," explains Professor David Eaton. "These mantle keels resisted tectonic recycling into the deep mantle, allowing the preservation of continents over geological time and providing suitable environments for the development of the terrestrial biosphere." His method takes into account important factors such as dwindling contribution of natural radioactivity to the heat budget, and allows for the calculation of other properties that strongly influence mantle evolution, such as bulk density and rheology (mechanical strength). "Our computer model emerged from a multi-disciplinary approach combining classical physics, mathematics and computer science," explains Eaton. "By combining those disciplines, we were able to tackle a fundamental geoscientific problem, which may open new doors for future research." This work provides significant new scientific insights into the formation and evolution of continents on Earth. University of Calgary (2013, September 16). Birth of Earth's continents: New research points to crust stacking, rather than upwelling of hot material. ScienceDaily. Retrieved September 18, 2013, from http://www.sciencedaily.com/releases/2013/09/130916122133.htm
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AGS Members… Geology Enthusiasts Needed!! If you are an AGS member and would like to contribute to the Professional Registration Committee by leading a lecture on one of the subjects listed below, then please contact me either by e-mail or at the monthly AGS meetings. The lecture should be for one hour followed by a Q&A session. We need different speakers for each workshop. Your volunteering to teach on one of these subjects is essential to the success of the Professional Registration Committee – we need more widespread participation by the AGS membership. Speakers can be compensated for expenses and will receive certificates to acknowledge their participation. The following content domains are covered in the Georgia Professional Geologist exams: A. General Geology B. Mineralogy, Petrology, & Petrography C. Sedimentology, Stratigraphy, & Paleontology D. Economic Geology & Energy Resources E. Structure, Tectonics, & Seismology F. Hydrology & Environmental Geochemistry G. Engineering Geology
H. Quaternary Geology, Geomorphology, & Surficial Processes
We do not "teach the test" our aim is to review fundamental concepts of the earth sciences and acquaint candidates with industry specific information not easily obtainable from the literature. Please inform anyone who might be interested in becoming a professional geologist of our workshop. Please consider joining us even if you are not a P.G. candidate. The workshops are interesting and informative. Ken Simonton, P.G., Chair John Salvino, P.G. Professional Registration Committee www.atlantageologicalsociety.org
The rarely seen geomorphology cartoon. Maybe there is a reason that the cannon of geomorphology humor is so thin… BB
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Now Showing in the Fernbank IMAX movie theater:
Penguins -- Set against a backdrop of dramatic snowy peaks and glacial crags, Penguins follows a brave king penguin on the journey of a lifetime. Watch this breathtaking, endearing and ultimately triumphant quest unfold on the biggest screen in town, Fernbank’s IMAX® Theatre. Hidden Universe -- Take a breathtaking tour of deep space through images captured by Hubble and the world’s most powerful telescopes. Explore galaxies and travel the terrain of Mars; witness images of celestial structures; and peer deep inside vivid clouds of nebula.
BOTH showing through January 2, 2014
Fernbank Museum of Natural History
Upcoming Public Programs and Events (All programs require reservations, including free programs)
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Fernbank Museum of Natural History 767 Clifton Rd, NE, Atlanta, GA 404-929-6400
Special Exhibits On View: http://www.fernbankmuseum.org/explore-exhibits/special-exhibitions
Marco Polo: Man & Myth Experience the story of the ultimate adventure traveler. Follow Marco Polo’s adventures along the Silk Road through a collection of more than 80 objects representing an epic journey that spanned 24 years and thousands of miles. Making its North American premiere at Fernbank Museum, this special exhibition features coins, ceramics, artworks, maps, and more. From Marco Polo’s homeland in Venice to his final destination in China, the exhibition reveals the many cultural influences and customs he observed, highlights the impact of exchanging ideas along the Silk Road, and sheds light on his encounters inside the Mongol Empire, including the Court of Kublai Khan. Along the way he became an experienced merchant, knowledgeable explorer and keen observer.
Exhibition galleries highlight the diverse landscapes and cultures encountered on his journey, which were chronicled in one of the most important travelogues of all time, The Travels of Marco Polo. Both man and myth today, he is forever recognized as the quintessential traveler. Tickets for Marco Polo: Man & Myth are included with Museum admission and are free for members. Click here for Fernbank downloadable resources: http://www.fernbankmuseum.org/discover-and-learn/downloadable-resources/
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AGS Committees
AGS Publications: Allison Keefer Phone (404) 657-8642 [email protected]
Career Networking/Advertising: Todd Roach Phone (770) 242-9040, Fax (770) 242-8388 [email protected]
Continuing Education: Currently Open
Fernbank Liaison: Chris Bean Phone (404) 929-6313 [email protected]
Field Trips: Josh Jenkins Phone (770) 421-3412 [email protected]
Georgia PG Registration: Ken Simonton Phone: 404-825-3439 [email protected] John Salvino, P.G. [email protected]
Teacher Grants: Bill Waggener Phone (404)354-8752 [email protected]
Hospitality: Tom Watson Phone (678) 358-6943 [email protected] Social Media Coordinator: Carina O’Bara [email protected]
Newsletter Editor and Membership Ben Bentkowski Phone (404) 562-8507,(770) 296-2529 [email protected]
Web Master: Kathaleen Bentkowski [email protected] www.atlantageologicalsociety.org
AGS 2013 Meeting Dates
Listed below are the planned meeting dates for 2013. Please mark your calendar and make plans to attend.
October 26th P.G. Study Class October 29th AGS meeting November 23rd P.G. Study Class (Need to verify date with Ken and John due to proximity to Thanksgiving) November 26th AGS meeting
December – no meetings - Happy Holidays 2014 January 28 AGS meeting February 25 AGS meeting March 25 AGS meeting April 29 AGS meeting May 27 AGS meeting June 24 Annual Social August 26 AGS meeting
AGS Officers
President: Nils Thompson [email protected] Phone (678) 486-2766 Vice-President: Cassidy Sutherland Phone (770) 492-8230 [email protected] Secretary: Rob White Phone (404) 321-5399 [email protected] Treasurer: Stacey Durden-Phillips [email protected]
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ATLANTA GEOLOGICAL SOCIETY
www.atlantageologicalsociety.org ANNUAL MEMBERSHIP FORM
Please print the required details and check the appropriate membership box. DATE: NAME:
ORGANIZATION:____________________________________________________________
TELEPHONE (1): TELEPHONE (2): EMAIL (1): EMAIL (2):
STUDENT $10 PROFESSIONAL MEMBERSHIP $25 CORPORATE MEMBERSHIP $100 (Includes 4 professional members, please list names and emails below) NAME: EMAIL: NAME: EMAIL: NAME: EMAIL: NAME: EMAIL: For further details, contact the AGS Treasurer: [email protected]. Please make checks payable to the “Atlanta Geological Society” and remit with the completed form to:
Atlanta Geological Society, Stacy Durden-Phillips, Treasurer, 2534 Centennial Commons View Acworth GA 30102.
CASH
CHECK (CHECK NUMBER: .)