Category Archives: PGS

Potomac Geophysical Society

PGS: Remote Sensing International Case Studies

PLEASE REPLY TO Cathy Enomoto at cenomoto@usgs.gov BY FEBRUARY 14TH IF YOU PLAN TO ATTEND DINNER AND/OR MEETING AT CROWNE PLAZA TYSONS CORNER BECAUSE AN ACCURATE HEAD COUNT IS REQUIRED BY THE RESTAURANT.

Dear PGS Members,

The February 18, 2016, meeting of the Potomac Geophysical Society (PGS) will be held at 7:00 p.m. at Crowne Plaza – Tysons Corner hotel, 1960 Chain Bridge Road, 22102. This location is within one-half mile of the Tysons Corner Metro station, near I-495, and has free parking available. Our private meeting room is located in the back of the Tuscan Grille restaurant on the second floor of the hotel. The optional dinner cost will be discounted to $30 for members in good standing (have paid dues), and $35 for non-members, and is inclusive of iced tea, coffee, tax and gratuity. Members and guests may attend the presentation after dinner for no charge; we estimate that the presentation will begin at 8:15 p.m. For attendees who arrive early, the social will be held in O’Malley’s Pub on the first floor of the Crowne Plaza hotel. Drinks may also be purchased in the private meeting room on a cash basis.

Social: 6:00-7:00 p.m. O’Malley’s Pub, first floor Crowne Plaza
Dinner: 7:00-8:15 p.m. Tuscan Grille, second floor Crowne Plaza
Meeting & Presentation: 8:15-9:30 p.m. Tuscan Grille, second floor Crowne Plaza

PLEASE reply to this email if you plan to attend the dinner and the presentation, or the presentation only. We want to be sure there are enough seats and meals.

Respectfully,

Catherine Enomoto, President
cenomoto@usgs.gov
703-648-6439

‘Remote Sensing International Case Studies’
Remote sensing, the collection of data without direct contact, is a greatly expanding source of spatial information from an approximate 100 operational spaceborne sensors augmented by traditional airborne systems and increasingly by Unmanned Aerial Systems. Perhaps the greatest need for these data is in developing countries and there is a long history of technology transfer in this context.

This presentation includes applied and basic science international case studies of remote sensing. There are examples from Nepal, Kenya and Afghanistan, among others including considerable field photographs. The basic science compares and integrates optical and radar imagery for land cover mapping.

Background Note: Barry Haack is a Professor of Geographic and Cartographic Sciences at George Mason University and a Visiting Scientist with the USGS National Headquarters. He has academic degrees in Geography from the University of Wisconsin, San Diego State University and the University of Michigan. He has held fellowships with NASA Goddard, the US Air Force and the Jet Propulsion Laboratory of Cal Tech as well as having served as a consultant to the UN, FAO, World Bank and various governmental agencies in Africa, Asia and South America. Dr. Haack is active in the America Society for Photogrammetry and Remote Sensing where he is a Fellow. He was a Fulbright Professor at the University of Dar es Salaam in Tanzania and a Visiting Scientist at the International Centre for Integrated Mountain Development in Kathmandu, Nepal.

PGS: Fairfax Urban Search and Rescue in Nepal

The Potomac Geophysical Society, November 19, 2015–directions below:

Fairfax Urban Search and Rescue in Nepal.

The description will be: After the April earthquake in Nepal, the urban search and rescue team from the Fairfax County Fire and Rescue Department responded and rescued two victims from collapsed structures.  The team is one of two search and rescue teams sponsored by the federal government to conduct international search and rescue.

John Morrison serves as a Planning Section Chief within the Urban Search and Rescue team, Virginia Task Force 1, which serves as one of the 28 domestic response teams under FEMA and as one of the two response teams under USAID/OFDA.  The planning section is responsible for situational awareness, information technology, mapping, finance and documentation while the team is deployed.  He has been a member of the team since 2003.

Meeting Room and Dining Arrangements: We 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, so we collect $25 from each member and $30 from each non-member. If a diner 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. Reception is at 6:00 p.m. downstairs in the Old Guard Lounge. We order dinner at 7:00 p.m. The presentation is at 8:30 p.m. Please note that the meal orders will be taken at 7:00 p.m. 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. Reservations are not necessary, however, we need a head count; so, if you wish to attend dinner, please inform Bob Fraser at 703-624-3965 or via email at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Please send changes of address or email to fraser.robert@comcast.net.

 

PGS venue changing in 2016

The monthly meetings of the Potomac Geophysical Society (PGS) for September through December, 2015, will be held at Fort Myer Officers Club in Arlington, Virginia, as in the past.  The optional dinner cost will be discounted to $25 for members in good standing (have paid dues), and $30 for non-members.  Members and guests may attend the presentation after dinner for no charge.

Starting in January and going through May, 2016, PGS will hold its monthly meetings on the third Thursday at Chili’s/On the Border Restaurant.  The restaurant with meeting room is located at 8053 Leesburg Pike, Vienna, VA, 22182.  This location is within one mile of the Tysons Corner Metro stop, near I-495, and has free parking available.  Our meeting room is located at the back of the On the Border restaurant.  The room will hold 22 people comfortably for a dinner meeting.  The wait staff and menu will be from Chili’s.  The optional dinner cost will continue to be discounted to $25 for members in good standing (have paid dues), and $30 for non-members.  The dinner cost will cover non-alcoholic drinks, tax, gratuity, and the speaker’s meal.  Members and guests may attend the presentation after dinner for no charge.

The officers of PGS look forward to experiencing this change in venue.  Please let us know if you have any questions.

Respectfully,

Catherine Enomoto, President

cenomoto@usgs.gov

PGS: Louisa, VA earthquake sequence

The Potomac Geophysical Society, October 15, 2015–directions below:

Observations on The Louisa County Earthquake Sequence.

Keith L. McLaughlin

Abstract: At 13:51:04 EDT 23 August 2011, an Mw 5.7 earthquake occurred in rural Louisa County VA, near the small town of Mineral. The MMI VIII event was widely felt in 13 states and caused an estimated $200-300 Million damage. The event has been called “The largest and most damaging earthquake in eastern US since Charleston SC 1886”.  Aftershocks continue. While the Central VA earthquake zone has a history of moderate (MMI V-VII) earthquakes, the zone has historically been sparsely monitored. Two seismic stations between 100 and 300 km of the main shock provide a tantalizing historical data set that may be successfully exploited using modern waveform cross-correlation methods.  The main-shock was a complex rupture and the aftershocks are distributed over a significant volume with a range of focal mechanisms. These factors present a unique challenge to developing correlation-based methodologies to “mine for aftershocks” and search for un-reported events. I will present work in progress using these developing methods to investigate the Louisa Sequence.

Bio: Dr. Keith Lynn McLaughlin, Leidos Technical Fellow

Ph.D., Geophysics, University of California, Berkeley, 1983. “Spatial Coherency of Seismic Waveforms” M.S., Geophysics, University of California, Berkeley, 1980. B.A., Physics, University of California, Berkeley, 1974

Dr. McLaughlin’s specialty is physics-based statistical analysis of geophysical sensing (seismic, acoustic, and EM). He developed methodologies for event magnitude estimation, localization accuracy assessment, seismic, acoustic and EM adaptive signal-processing and physics-based target-based multi-mode multi-node fusion (M3NF) for MASINT exploitation architectures. Over the last three decades he worked on ground motion prediction (earthquake, explosion, machinery, vehicles, …), seismic and infrasound location, event discrimination, yield estimation, geothermal exploration, and persistent monitoring of human activities from unattended ground sensors. He was co-PI with VaTech under the DARPA Heterostructural Uncooled Magnetic Sensor (HUMS) program. He served as the PI and PM for the DTRA “IMS Group 2 Location Calibration Consortium”. He served as domain expert and US delegate to multiple bi-lateral and multi-lateral international conferences and workshops.

1998 to Present. Senior Scientist and Technical Fellow, Leidos (formerly SAIC).  Provides consulting and contributing technical services to multiple programs across the corporation. Serves as Chief Scientist, PI, and/or PM on multiple R&D efforts.

Meeting Room and Dining Arrangements: We 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, so we collect $25 from each member and $30 from each non-member. If a diner 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. Reception is at 6:00 p.m. downstairs in the Old Guard Lounge. We order dinner at 7:00 p.m. The presentation is at 8:30 p.m. Please note that the meal orders will be taken at 7:00 p.m. 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. Reservations are not necessary, however, we need a head count; so, if you wish to attend dinner, please inform Bob Fraser at 703-624-3965 or via email at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Maurer on “The curse of dimensionality in exploring the subsurface”

2015 Near Surface Honorary Lecturer
The curse of dimensionality in exploring the subsurface
Presented by Hansreudi Maurer
ETH Zurich, Switzerland
The term “curse of dimensionality” refers to increases in the dimensionality of model spaces that result in undesirable increases in data sparsity, such that model parameters are no longer sufficiently constrained by the data. Although the term is usually employed in combinatorics, machine learning, and data mining, it is also directly relevant for many problems in exploration geophysics. The most obvious applications are 3D tomographic inversions, which typically include very large numbers of unknowns.
There is a further “curse of dimensionality” and related data sparsity that may impede many geophysical investigations: 3D surveys typically involve the acquisition of data using only a 2D array of sensors distributed across the Earth’s surface. As a consequence, procedures for imaging the subsurface are missing data recorded in the third dimension, depth. Similar problems affect 2D inversions of (1D) profile data.
Computational problems that need to be overcome in large-scale tomographic inversions are additional issues associated with the “curse of dimensionality”. In particular, the rapidly emerging field of realistic 3D full-waveform inversions of elastic and anisotroic data is hitting the limits of current computer facilities. Seemingly ever increasing computing power will undoubtedly be beneficial for such endeavors. Nevertheless, suitable model parameterizations that offer appropriate spatial resolution while keeping the inversion problem computationally tractable will continue to be critical elements of any high dimension inversion endeavor.
Because of the large computational costs and the difficulties to cover extensive areas with geophysical sensors in complicated terrain, many land surveys continue to involve data acquisition along profiles. Such surveys will play a significant role for the foreseeable future. When solving the associated 2D inversion problems, the “curse of dimensionality” strikes again. The underlying 2D assumption that subsurface properties and topography do not change in the third dimension, that is, perpendicular to the tomographic plane, is often unjustified.
The problem of data sparsity can be partially alleviated by employing optimized experimental design and optimized data parameterization approaches. These techniques identify experimental configurations and data representations that optimize data information content and resultant models in a cost-effective manner.
In this lecture, I will illustrate the “curse of dimensionality” by means of several examples from near-surface geophysics. I will present a variety of options for addressing the related problems, including experimental design techniques and optimized model parameterization strategies. I will also discuss problems and remedies related to out-of-plane features in 2D elastic full-waveform inversions.

Biography
Hansruedi Maurer is professor for exploration and engineering geophysics at ETH Zürich, Switzerland. His research interests span from algorithmic developments for geophysical tomography to innovative field studies concerned with natural hazards, storage of dangerous waste, exploration of deep geothermal reservoirs, cryosphere research and several other areas, where geophysical techniques provide useful information. A key aspect of his research is the tight coupling of latest developments in numerical modelling and inversion theory with the solution of problems that arise in field applications of magnetic, geoelectric, inductive electromagnetic, ground-penetrating radar and seismic methods. Moreover, he is one of the leading scientists in geophysical experimental design. His contributions in this relatively new research discipline were awarded with the Best Poster Award at the 1997 meeting of the Society of Exploration Geophysics and the 2004 Best Paper Award in Geophysics. He has served as an Editor for Geophysics, and he is an active member of several national and international scientific boards.

An invitation to join the Potomac Geophysical Society

Dear PGS Members and Associates,

It is my pleasure to invite you to join the Potomac Geophysical Society (PGS) for the 2015-2016 season. PGS is a local section of the Society of Exploration Geophysicists (SEG) and an affiliate society of the American Geophysical Union (AGU). Our goal is to encourage interaction among those in the region around Washington, D.C., who have an interest in geophysics or related earth sciences. Over the years, members of PGS have included individuals working in a broad range of government, academic, and private sector jobs.

PGS has continued to remain active and vital largely due to the interest of a dedicated group of loyal members. We would like to encourage you to be a part of this group. If you have not been a member, we ask that you join and attend this year. PGS cannot maintain its vitality without your support. PGS members receive a discounted price of $25.00 for dinner at the monthly meetings; non-members will be required to pay $30.00 for dinner. Members and non-members may attend the presentation only at no charge.

PGS will meet on September 24, 2015, (fourth Thursday); then will meet on the third Thursday of each month at the Officers’ Club at Fort Myer in Arlington, VA. The meetings typically include a social hour starting at 6:00 PM, followed by an optional dinner served at 7:30 PM, and a topical discussion by an invited speaker beginning at 8:30 PM. Our 1st Vice President, Marc Buursink, is busily working on arranging a very interesting series of talks for the upcoming season. If you have recommendations for speakers or discussion topics, any of the officers will be happy to hear from you.

For additional background, information, directions to the meetings, and breaking news about PGS, please check out our website at: http://www.potomacgeophysical.com.

We hope you will be able to join us on a regular basis in 2015-2016. We look forward to seeing you!

On behalf of the PGS Officers,
Catherine Enomoto

President: Catherine Enomoto, U.S. Geological Survey, cenomoto@usgs.gov
1st Vice President: Marc Buursink, U.S. Geological Survey
2nd Vice President: Victor Oancea, SAIC
Secretary: Bob Fraser, U.S. Geological Survey (retired)
Treasurer: Joe Bennett, Leidos (retired)
Website Administrator: Jay Pulli, Raytheon BBN Technologies

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.