Category Archives: PGS

Potomac Geophysical Society

AEG/PGS: Conventional Tunneling at Tyson’s Corner

BWH Section of the Association of Environmental &

Engineering Geologists and the Potomac Geophysical Society

Date: Thursday May 21, 2015

www.aegweb.org

www.potomacgeophysical.com

JOINT SECTION MEETING

Baltimore MD – Washington DC – Harrisburg PA

The Meeting will be held at the Amphora Restaurant, 377 Maple Ave., Vienna VA, 6:00-8:30pm. Reservations are necessary,  we need a head count for the restaurant, so, if you wish to attend dinner ($40, members; $45, non-members), please inform Bob Fraser by May 15th at 703-624-3965 (takes both voice and cell text messages) or via E-mail at fraser.robert@comcast.net. Non-members and guests are welcome but must have a reservation. Let’s make this joint meeting a success: make a reservation!

TOPIC: Conventional Tunneling (SEM) at: Tysons Corner, Virginia

PRESENTER: Vojtech Gall, Ph.D., P.E. Gall Zeidler Consultants, Ashburn, VA

BIO: Dr. Gall is a Principal of Gall Zeidler Consultants, a tunnel engineering and consulting company headquartered in Northern Virginia. He has over twenty-five years of experience in the design, construction, and construction management of tunnels and underground structures. He frequently serves on expert review panels dedicated to the investigation and improvement of tunneling schemes ranging from initial inception stages through final design development at bid document level. His services relate to a wide variety of facilities ranging from hydro-power schemes in remote settings to complex transit structures at shallow overburden in difficult, over-built urban settings. He has led tunneling efforts on large infrastructure project such as Dulles Metrorail in DC, the Caldecott 4-th bore tunnel in San Francisco and the East Side Access project in New York City. He holds M.Sc. and B.Sc. degrees in Civil Engineering from the RWTH University in Aachen, Germany, a M.Sc. in Mineral Engineering from the University of Alabama and a Ph.D. in Civil Engineering from the University of Maryland. He is a registered Professional Engineer in 18 states and has authored over 40 technical publications on the subjects of tunneling.

ABSTRACT: The Metropolitan Washington Airports Authority (MWAA) is constructing the Dulles Corridor Metrorail Project (DCMP), which will extend Washington Metropolitan Area Transit Authority’s (WMATA) rail services from the Metrorail Orange Line in Fairfax County, Virginia to Route 772 near Ashburn in eastern Loudoun County, Virginia. The extension will be known as the Silver Line and once completed will add 23 miles to the existing Washington Metro System. The project was subdivided in two phases. Phase I segment is 12 miles long and involves 5 stations (two at grade and three elevated) and was opened to public in 2014. Phase II will extend the rail by another 11 miles with a station at Dulles International Airport and a terminus station in Ashburn.

Both phases use the design-build (DB) delivery method. Phase I was constructed by Dulles Transit Partners (DTP) a Joint Venture of Bechtel and URS and included twin 1,700 feet long single track, 22 feet diameter conventional tunnels (excavated by the Sequential Excavation Method or SEM) that are situated in the urban setting of Tysons Corner.

The presentation will address design and construction of these soft ground tunnels that emerged as the most feasible alternative to practically all other tunneling methods including open and closed face TBM drives and cut-and-cover techniques. Tunneling was accomplished with shallow overburden of as low as about 7 feet from the tunnel crown. Because of the shallow depth, soft ground conditions, and the need to control settlements, the tunnel design included use of a double row grouted pipe arch canopy as pre-support for the first 300 feet of excavation and a single row pipe arch canopy for the remaining length of tunnels thereafter. A real-time monitoring of the surface when tunneling the first 90 m under International Drive was implemented to assure VDOT of the tunneling performance.

PGS: DC Clean Rivers Project

The March 19, 2015 meeting of the Potomac Geophysical Society will be held at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Timothy J. King, P.G. AECOM Germantown, Maryland

The DC Clean Rivers Project is an ongoing program being implemented by DC Water to reduce combined sewer overflows into the Anacostia and Potomac Rivers and Rock Creek. The Project involves construction of a series of storage and conveyance tunnels and related infrastructure to capture and subsequently treat combined sewer water from heavy rainfalls to reduce impacts to the region’s waterways.

Mr. King’s presentation will discuss the application of geophysical investigation methods to the planning and design of tunnels, shafts and related infrastructure associated with the project. Investigations have included seismic surveys to assess subsurface stratigraphy and depth to bedrock, borehole geophysical logging to characterize bedrock discontinuities, multichannel analysis of surface waves (MASW) to delineate buried channels, vertical seismic profiling for seismic design, and side-scan sonar surveys to delineate underwater obstructions.

Biography

Timothy King is a Principal Geologist at AECOM (formerly Woodward-Clyde Consultants and URS Corporation) in Germantown, Maryland. He built and is the leader of the geophysical services team at URS/AECOM. His experience includes engineering geophysics, engineering geology, and hydrogeology applied to site investigations to evaluate subsurface conditions related to tunnels, mines, highways, bridges, dams, and other civil infrastructure. He has been responsible for technical and management aspects of investigations at hundreds of sites across the United States and has worked on projects in Africa, South America, Europe and New Zealand.

Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Geology and Public Policy – Recent Issues in Virginia

The February 19, 2015 meeting of the Potomac Geophysical Society will be held at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Geology and Public Policy – Recent Issues in Virginia

David B. Spears, State Geologist

Virginia Department of Mines, Minerals and Energy

Government decision makers are faced with difficult choices when it comes to public policy regarding energy and mineral resources. Our nation is heavily dependent on fossil fuels, radioactive isotopes, and rare earth elements that often must be imported from foreign countries to meet U.S. demand. Even though developing our own domestic supplies has obvious strategic advantages, such development often conflicts with other societal priorities such as environmental protection and social justice. To further complicate matters, conflicting pressure is brought to bear on policy makers by an uninformed or misinformed populace that is generally anti-development, and by pro-development businesses who have a financial interest in resource development. In this presentation, Virginia’s State Geologist will use recent, Virginia-specific examples such as uranium mining, offshore drilling, and shale gas to highlight the ways in which government-based geoscientists play a unique role in providing scientific guidance in public debates about how to best manage our nation’s energy and mineral resources.

David Spears is the State Geologist of Virginia, a position residing in the Department of Mines, Minerals, and Energy. He is responsible for coordinating the work of the Division of Geology and Mineral Resources, a small group of geoscientists focused on mapping Virginia’s geology, mineral resources, energy resources, and geologic hazards such as earthquakes, landslides, and sinkholes. In recent years, the State Geologist has played an increasing role in responding to public policy issues such as offshore drilling, natural hazards, and hydraulic fracturing. David received a B.S. in Geology from Lafayette College and a M.S. in Geology from Virginia Tech. He began his professional career in the petroleum industry before coming to Virginia state government in 1993. A native of New Jersey, he currently resides in Buckingham County in central Virginia. In 2012, David received the Bradley Prize from the Geological Society of Washington for his presentation about geology and public policy.

Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS January meeting: Electromagnetic Survey of Potomac River headwaters

The January 15, 2015 meeting of the Potomac Geophysical Society will be held January 15 at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Electromagnetic Survey of the Headwaters of North Branch of Potomac River, Important Tributaries, and Impacting Mines

Paul Petzrick, Maryland Power Plant Research Program, Annapolis, Maryland

In 1999, the National Energy Technology Laboratory (NETL) acquired a Helicopter Electromagnetic Survey (HEM) of the Kempton/Coketon Mine Complex for the Maryland Power Plant Research Program (PPRP). NETL’s interest was in studying remote sensing as a means of identifying water quality problems from mining, and PPRP’s interest was in planning geoengineering projects to permanently restore water quality in streams degraded by abandoned pre-law mines. The 1999 HEM revealed important benefits and limitations of this type of survey that might now be performed by drones. The data from the 1999 survey is particularly important when coupled with other data collected for PPRP by Garrett College and the Western Maryland Regional GIS Center in understanding the massive two-State, 64 square kilometer, surface and underground mine complex that disturbs the headwaters of the Potomac River.

Mr. Petzrick’s presentation will discuss interpretation of the HEM data, the importance of software for conversion of the data to useful graphics for planning restoration projects, and alternate methods of remote sensing and their conversion to useful graphics. The data and its interpretation in each case has been the subject of significant review by NETL and its support contractor and similarly by experts at PPRP’s support contractor, Environmental Resources Management, Inc. The importance of historical information and utilization of water quality data as a tool in assessing environmental issues will also be addressed.

Biography

Paul Petzrick is a Senior Engineer and Scientist at the Maryland Power Plant Research Program (PPRP) with a focus on Civil and Environmental Engineering. He has been with this Program in the Maryland Department of Natural Resources for 23 years after finishing 30 years of Federal service that included 20 years as a Navy Civil Engineer Corps officer and 7 years of Senior Executive Service at the U.S. Department of Energy. He had applied mathematics education at the University of Wisconsin and has Engineering Degrees from the U.S. Naval Academy, RPI, and Princeton (M.S. 1966). At PPRP he is primarily responsible for the beneficial use of by-products (ash and CO2) of producing electricity.

Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Evolution of the Beaufort Sea

The October 16, 2014 meeting of the Potomac Geophysical Society will be held October 16 at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Seismic Evidence for the Geologic Evolution of the Alaska Beaufort Sea and Adjacent Canada Basin

Dave Houseknecht, U.S. Geological Survey, Reston, Virginia

Integration of 2-D reflection seismic, gravity, and sparse exploration well data from the offshore Alaska Beaufort shelf and slope provides new perspectives on the dynamic tectonic evolution of this Arctic margin. The Beaufort shelf is considered a rift shoulder that developed during Jurassic to Early Cretaceous opening of the Canada Basin, and previous work considered much of the pre-Cretaceous stratigraphy to have been eroded beneath the breakup unconformity. However, reprocessed and newly collected seismic data demonstrate the presence of highly attenuated crust and Jurassic to Lowermost Cretaceous syn-rift strata beneath much of the shelf. Moreover, older strata are present beneath the syn-rift succession, and these include Upper Paleozoic and perhaps Triassic strata, the latter of which may include oil-prone source rocks.

The north-vergent front of the Brooks Range thrust belt is extant beneath the eastern Beaufort shelf, and forms a tectonic wedge and syntectonic wedge-top basin system active since the Paleocene. Upper Paleozoic to Cretaceous strata are deformed by thrust faults and folds within this wedge, and reconstruction of syn-rift extension is difficult as a result. Paleocene through Pliocene strata display a spectrum of growth geometry beneath the shelf and slope, a reflection of syntectonic wedge-top deposition.

This ongoing research contributes to a better understanding of the tectonic evolution of the Alaska Arctic margin, and of the petroleum potential of the region. The results are being used to inform policy makers regarding a disputed maritime boundary between the U.S. and Canada, as well as potential extended continental shelf claims under the U.N. Convention on the Law of the Sea.

Biography

Dave Houseknecht is a research geologist with the U.S. Geological Survey (USGS) with a focus on basin analysis, geological controls of petroleum resource distribution, and petroleum resource assessment. This work is mainly concentrated in Arctic Alaska and adjacent Arctic regions. He frequently represents the USGS scientific perspective on petroleum resources in ANWR, NPRA, and other areas of Alaska and the global Arctic to the Administration and Congress. Dave joined the USGS in 1992, serving as Energy Program Manager through 1998 and then moving to a research position. Previously, Houseknecht was a professor of geology at the University of Missouri (1978-1992) and consultant to the oil industry (1981-1992), working on domestic and international projects. He received geology degrees from Penn State University (Ph.D. 1978, B.S. 1973) and Southern Illinois University (M.S. 1975).

Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Crustal-Scale Mass and Heat Transfer During the Run-up to a Super Eruption

The May, 2014, meeting of the Potomac Geophysical Society will be held May 15th at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Crustal-Scale Mass and Heat Transfer During the Run-up to a Super Eruption, James E. Quick1, Silvano Sinigoi2, Gabriella Demarchi2, Ian Richards1, Rita Economos3 (1Huffington Department of Earth Sciences, Southern Methodist University, Box 750395, Dallas, TX 75205. 2Dipartimento di Scienze della Terra, Università di Trieste, via Weiss 8, 34127 Trieste, Italy. 3Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095-1567

Abstract: A virtually complete crustal section in the Sesia Valley of northwest Italy provides a unique opportunity to directly constrain crustal-scale transfer of mass and heat beneath a continental volcanic system. Capping the section, a bimodal volcanic complex containing a >15-km-diameter rhyolitic caldera is intruded by a 7- to 8-km-thick granitic pluton that is rooted in migmatitic paragneiss at mid-crustal levels. An 8-km-thick gabbroic body, “magmatically underplated” at >15 km depth, intrudes the paragneiss. Consistent with a cause-and-effect relationship between magmatic underplating in the deep crust and silicic plutonism and volcanism at high crustal levels, SHRIMP U/Pb zircon ages for volcanic, granitic and underplated gabbroic rocks cluster within a relatively narrow time window of ~290 to ~280 Ma. A Concordia age of 282 + 0.75 Ma on zircons from the caldera ignimbrite indicates that caldera formation occurred late in the evolution of this magmatic system. Field relations and geochemistry constrain the thermal history of the Sesia section and the processes of magmatic underplating, crustal anatexis and assimilation, and hybridization during its magmatic evolution. Magmatic underplating was accommodated by crustal extension, which is recorded by structures produced by the flow of gabbroic cumulates downward and away from a small magma chamber perched near the top of the intrusion. Heat from the underplated gabbro induced anatexis in country-rock paragneiss, producing granitic melts that migrated higher in the crust. Eu and Ba enrichments, εNd < -2.5, 87Sr/86Sr >0.7075, and δ18O > 8 indicate that the parental melt of the underplated gabbro had ingested ~24% to 40% assimilant consisting of paragneiss previously stripped of a granitic component. Peraluminous compositions of the granitic and volcanic rocks indicate that anatectic melting of metapelitic paragneiss was a contributing source, but 87Sr/86Sr ~ 0.710 and whole-rock δ18O ranging from 10 to 11.5 are intermediate between the compositions of the paragneiss (87Sr/86Sr ~ 0.715 and δ18O from 11 to >15) and the underplated gabbro, indicating that late-stage, residual melts produced by fractional crystallization of the underplated gabbro also contributed to the formation of granite and silicic volcanic rocks. A 1-D, finite-difference thermal model utilizing these constraints and incorporating advection and energy-constrained assimilation reproduces the thicknesses of lithologies observed in the field and indicates that: (1) focused delivery of mantle melt was efficient in driving anatexis in overlying crustal rocks, (2) migration of anatectic melts to the upper crust was efficient in removing heat from the underplated gabbro and restricting its thermal impact on the overlying crust, and (3) growth of lower- and upper-crustal plutons involved incremental assembly under conditions favoring creation of large volumes of crystal mush rather than large classic magma chambers.

Bio:  James E. Quick is the Associate Vice President for Research, Dean of Graduate Studies, and Professor of Earth Sciences at Southern Methodist University (SMU). Prior to his appointment at SMU, he was employed by the US Geological Survey for 27 years in various capacities including Team Chief Scientist for the Eastern Regional Geologic Mapping and Earth Surface Processes Teams, and Program Coordinator for the Volcano Hazards Program. He earned a BSc in Geology at UCLA, an MSc in Mineralogy and Petrology at the University of Minnesota, and a PhD in Geology at Caltech. For the last 25 years, Professor Quick’s research has focused on the Sesia Valley in northern Italy as a natural laboratory to understand the processes that influence the composition and the formation of igneous rocks. In this area, he and his Italian colleagues have demonstrated that tilting and uplift during the Alpine orogeny exposed the magmatic system beneath a Permian supervolcano to an unprecedented depth of >25 km. These results, which were recognized by the Geological Society of Italy with the Capellini Medal in 2010, led to the creation of a UNESCO Geopark in 2013, and resulted in Professor Quick’s induction in January as an honorary citizen of Borgosesia, the principal city of the Sesia Valley. In his presentation, Professor Quick will use boundary conditions developed in the Sesia Valley to address crustal-scale mass transfer and thermal evolution within an evolving magmatic system during the lead up to a super eruption.

Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001540-888-3001 or via E-mail at fraser.robert@comcast.net.If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email tofraser.robert@comcast.net.

PGS: Space Geodesy Project

The April, 2014, meeting of the Potomac Geophysical Society will be held April 17th at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Abstract: NASA’s Space Geodesy Project, Stephen M. Merkowitz, NASA Goddard Space Flight Center, Greenbelt, MD: NASA’s Space Geodesy Project (SGP) recently completed a prototype core site as the basis for a next generation Space Geodetic Network that is part of NASA’s contribution to the Global Geodetic Observing System (GGOS). This system is designed to produce the higher quality data required to establish and maintain the Terrestrial Reference Frame and provide information essential for fully realizing the measurement potential of the current and future generation of Earth Observing spacecraft. The prototype core site is at NASA’s Geophysical and Astronomical Observatory at Goddard Space Flight Center and includes co-located, state of-the-art, systems from all four space geodetic observing techniques: Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite Systems (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). A system for monitoring of the “ties” between these four systems is an integral part of the core site development concept and this specific prototype. When fully implemented, this upgraded global network will benefit in addition to the ITRF, all other network products (e.g. precision orbit determination, local & regional deformation, astrometry, etc.) that will also be improved by at least an order of magnitude, with concomitant benefits to the supported and tracked missions, science projects, and engineering applications. This presentation will summarize the results of the prototype site demonstration and provide the motivation and plans for NASA’s next generation geodetic network.

Biography:  Stephen Merkowitz is a scientist and project manager at NASA Goddard Space Flight Center. His research interests include: fundamental tests of General Relativity, lunar and interplanetary laser ranging, and space geodesy. He received his PhD in Physics from Louisiana State University working on gravitational wave antennas, and continued this research for two years in Frascati, Italy on a National Institute for Nuclear Physics (INFN) fellowship. In 1998 he became a Research Associate at the University of Washington where he performed experimental tests of General Relativity and measurements of Newton’s gravitational constant (which remains the most precise measurement of “big G” to date). In 2000, he moved to NASA Goddard to serve as Deputy Project Scientist for the LISA Project, a space based gravitational wave mission. In 2009, Merkowitz went on a yearlong detail to the Executive Office of the President covering Physical Science and Engineering for the Office of Science and Technology Policy, followed by a detail at NASA Headquarters as Assistant Director of the Astrophysics Division. He returned to Goddard in 2011 and now manages NASA’s Space Geodesy Project and is Principal Investigator for the Global Positioning System Laser Retroreflector Array.

Meeting Room and Dining Arrangements: We now meet in the glassed-in room at the back of the main dining room—The Fife and Drum. We order individually from the Club menu, which has a nice variety of dinner offerings. We pay a single bill (I pay it with my Officers Club credit card), so we collect at least $25 from each diner with the agreement, that if one orders more than $20 in food and drink, he adds the amount over $20 to his contribution. The $5 overcharge goes to the Room Fee, Tax, Gratuity, and the Speaker’s Dinner. We collect on the Honor System. We did this throughout the last year, and it worked well. This room change and use of the menu have greatly reduced the loss that we have incurred in the past for having fewer than 20 people dining, and the change has preserved the viability of using the Officers Club for our meetings.

Reception at 6:00. Order Dinner at 7:00. Talk at 8:30 PM. Please note that the meal orders will be taken at 7:00. Allow 15 minutes for security entering Ft. Myer as all civilian vehicles are searched. To ensure access to and from Fort Myer use the Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001540-888-3001 or via E-mail at fraser.robert@comcast.net.If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email tofraser.robert@comcast.net.