Author Archives: Callan Bentley

UMD: Arevalo on planetary mass spectrometry

University of Maryland 2016 Geology Colloquium Series

Friday, November 18th 2016 at 3:00 pm
in PLS 1140

Ricardo Arevalo
NASA-GSFC

Planetary Exploration and the role of in situ mass spectrometry

Top-priority science questions drive the course of NASA (and ESA) mission selection, and are defined openly by groups of scientists, engineers and planetary advocates. As the ambitions of the community evolve, so do the technologies required to address them. For decades, mass spectrometers have served as low-risk, cost-efficient means to explore the inner and outer reaches of the solar system. Legacy analyzers have characterized a range of planetary environments, including the lunar exosphere, the surface of Mars, and the atmospheres of Venus, Mars and outer planets. However, the collection of complicated mass spectra and detection of organic compounds on Mars and Titan, coupled with ground-based measurements of organics observed in meteorites and cometary materials, has underlined the importance of molecular disambiguation in next generation instruments. In response to these demands, next generation mass spectrometers promise: compatibility with ! chemical separation techniques, such as two-step ionization methods and liquid or gas chromatography; isolation/enrichment of targeted ion signals and intentional fragmentation of precursor (or “parent”) molecules; and, intrinsically higher mass resolving powers to distinguish compounds with nearly identical mass-to-charge ratios.

Here, a review is provided on the process by which missions concepts are formulated, and the evolution of mass spectrometry as a versatile analytical tool for probing the chemical compositions of high-priority planetary environments.

UMD Geology: van Keken on computational geodynamics

2016 Geology Colloquium Series

Friday, November 11th 2016 at 3:00 pm
in PLS 1140

Peter van Keken
Carnegie Institution for Science

A computational geodynamicist’s journey through the Earth in three acts: chemical geodynamics, mantle plumes and subduction zones.

PSW seminar: Evolution of the butterflies

The Paleontological Society of Washington

7:00 pm, Wednesday, November 16

National Museum of Natural History, Constitution Ave. entrance

Evolution of moths and butterflies – the challenges of gathering reliable evidence from a poor fossil record

Maria Heikkila

Peter Buck Postdoctoral Fellow at the NMNH, Department of Paleobiology and Department of Entomology

A full understanding of the evolution of moths and butterflies (Lepidoptera) requires a robust time frame for the diversification events of the major lineages and the behavioral and structural novelties they exhibit. Fossils are essential in divergence time estimates, but lepidopterans are poorly represented in the fossil record. The known fossils have been minimally studied, many remain undescribed, and nearly all lack convincing assignments of systematic position. The aim of my work is to critically review the identifications of the important known fossil Lepidoptera.

Non-Smithsonian visitors will be escorted from the Constitution Ave. entrance of the NMNH to the Q?rius auditorium at 6:50 and 6:55 p.m. Society members will host the speaker for dinner at the Elephant & Castle (1201 Pennsylvania Ave.) prior to the meeting. Members may meet at the restaurant or inside the Constitution Ave. entrance of the NMNH at 5:00 and walk to the restaurant as a group.

http://nmnh.typepad.com/paleontological_society

AEG: Shana Carroll on Geopier Rammed Aggregate Case Studies

Notice of Meeting

Announcement from the BWH Section of the

Association of Environmental & Engineering Geologists

Date: Wednesday 11/16/2016

http://www.aegweb.org

SECTION MEETING

Baltimore MD – Washington DC – Harrisburg PA

 TOPIC: Geopier Rammed Aggregate Pier™ Applications & Regional Case Studies

 PRESENTER: Ms. Shana Carroll, P.E., Northeast Preconstruction Manager; GeoStructures, Inc.

Rammed aggregate pier systems are a ground improvement technology that can be used to increase bearing capacity and control settlement of buildings, tanks, Retaining walls and embankments to close tolerances.  Depending on site requirements, RAP systems can be installed using replacement (Geopier GP3®) or displacement (Geopier Impact®) methods. RAP systems are used to reinforce good to poor soils, including soft to stiff clay and silt; loose to dense sand; organic silt and peat; variable, uncontrolled fill; and soils below the ground water table. They can be used as an alternative to deep foundations or over-excavation, and provide cost and time savings on sites where poor soils and/or existing undocumented fill are a concern in terms of bearing capacity and settlement. This presentation reviews fundamental Geopier design and construction techniques and includes regional case studies such. Projects discussed include the National Cancer Institute’s Advanced Technology Research Facility located in Frederick Maryland and underlain by karst geology in the Piedmont Province, the Gaylord National River Ballroom located in National Harbor, MD in the Coastal Plain Province, and the George Mason University Fenwick Library in the Piedmont Province.

ABOUT THE PRESENTER:

 Shana Carroll currently serves as Northeast Preconstruction Manager for GeoStructures, Inc. and was formerly an Engineer with GeoSyntec, Inc. Shana has been involved in the design, estimating, and pre-construction management of specialty geotechnical systems throughout the East Coast since 2001. Shana holds a B.S. & M.S. degree in Civil and Environmental Engineering from Bucknell University and is a registered Professional Engineer in 5 states.  She is the immediate past president of the Baltimore Chapter of American Society of Professional Estimators (ASPE) and on the Program Committee for the National Capital Section Geotechnical Executive Committee of the American Society of Civil Engineers (ASCE). In her spare time, Shana enjoys writing about topics related to young professionals on her blog (www.outofthecube.net) and traveling.

MEETING INFORMATION:

 DATE: Wednesday November 16th, 2016

TIME:  6:00 pm to 8:00 p.m.

LOCATION:

Brewer’s Alley

124 N Market Street

Frederick, Maryland

COST (lunch & meeting):

Members:                   $40

Non-members:          $45

Discounts Available:

Students save $20

Retirees save $10

MEETING SCHEDULE:

6 p.m. to 6:30 p.m.                            Social & Check-In

6:30 p.m. to 7:00 p.m.                      Dinner

7:00 p.m. to 8:00 p.m.                      Section Business & Presentation

2015-16 AEG-BWH OFFICERS

Chair:  William Mikalik,   Applied Environmental, Inc., (703) 648-0822, wmikalik@appenv.com

Vice Chair: R. Drew Thomas, ECS Mid-Atlantic, LLC, (703) 995-1717, dthomas@ECSLimited.com

Treasurer:  Ashley Hogan, GeoCapital Engineering, LLC Inc., (703-926-5438) ahogan@geocapeng.com

Secretary: Katelyn Vieten, ECS Mid-Atlantic, LLC, (703) 471-3835, kvieten@ECSLimited.com

RESERVATIONS:

To reserve a seat, please visit our website & E-Pay System at:

www.AEG-BWH.org

Or email Katelyn Vieten

by Monday, November 14th, 2016 at  KVieten@ecslimited.com

Upcoming Events:

  • Wednesday, December 21, 2016 – Holiday Party (Location TBD)
  • Thursday January 12, 2017 – Jahn’s Lecturer (Location TBD)
  • April 7-9, 2017 – Spring Symposium (James Madison University)

PGS: Schmerr on Greenland’s firn aquifer structure

Please reply to the Potomac Geophysical Society <dcgeophys@gmail.com> by November 14 by noon if you plan to attend the dinner and/or the meeting at Crowne Plaza Tysons Corner.  Please find the flyer for this talk attached this email, feel free to post and spread the word.

Please join us for the November 17, 2016, meeting of the Potomac Geophysical Society (PGS) 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 students, and $40 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.

This Month’s Talk:  Active Source Seismic Investigation of Firn Aquifer Structure in Southeastern Greenland by Nick Schmerr, University of Maryland

Abstract:

In 2011, it was discovered that there is perennial storage of water in the firn of the southeastern Greenland ice sheet, a region of both high snow accumulation and high melt. This aquifer is created through percolation of surface meltwater downward through the firn, saturating the pore space above the ice-firn transition. The aquifer may play a significant role in sea level rise though storage or draining freshwater into the ocean. Our team carried out a series active source seismic experiments that used refracted P-wave arrivals, inverted with a transdimensional Bayesian approach, to identify the seismic velocities associated with the base of the aquifer. When our seismic approach is combined with a radar sounding of the water table situated at the top of the firn aquifer, we are able to quantify the volume of water present. In our study region, the base of the aquifer lies on average 27.7±2.9 meters beneath the surface, with an average thickness of 11.5±5.5 meters. We found the aquifer had an average water content of 26.7±6.3%, with considerable variation in volume fraction of water along the studied regional flow line. Between 2015 and 2016, we observed a 1-2 km uphill expansion of the aquifer system, with a site dry in 2015 with over 4000 kg m-2 water in 2016. We estimate the volume of water stored in the aquifer across the entire region upstream of Helheim glacier to be 7.9±3.3 gigatons. Elucidating the volume of water stored within these recently discovered aquifers is vital for determining the hydrological structure and stability of the southeastern Greenland ice sheet.

Bio

Dr. Schmerr has over a decade and a half of experience in seismology and geophysical research on planetary objects. He received his PhD in geophysics from Arizona State University in 2008 where he worked with Dr. Ed Garnero on deep Earth research topics. He was a postdoc at the Department of Terrestrial Magnetism at the Carnegie Institution of Washington from 2008-2010 where he worked on terrestrial mantle seismology with Drs. Paul Silver and David James. He went on from DTM to another postdoctoral position at NASA Goddard from 2010-2013, where he became involved in a number of planetary research problems, including studying the interiors of the Moon, Mars, and the icy worlds of the outer Solar System. He has since become an assistant professor at the University of Maryland in the Department of Geology where he leads a group of 3 PhD students and multiple undergraduates in Earth and planetary research. He has conducted seismic experiments in the United States, Greenland, and Canada, has grown his interests in terrestrial and cryosphere seismic science. Dr. Schmerr is a science collaborator on the upcoming InSight mission to place a seismometer on Mars. He resides in Seabrook, MD with his wife, Dr. Amy McAdam.

“Planets in a bottle” – JHU’s Hörst @ UMD

2016 UMD Geology Colloquium Series

Friday, November 4th 2016 at 3:00 pm
in PLS 1140

Sarah Hörst
Johns Hopkins University

Planets in a bottle: Exploring planetary atmospheres in the lab

From exoplanets, with their surprising lack of spectral features, to Titan and its characteristic haze layer, numerous planetary atmospheres may possess photochemically produced particles or haze. With few exceptions, we lack strong observational constraints (in situ or remote sensing) on the size, shape, density, and composition of these particles. Photochemical models, which can generally explain the observed abundances of smaller, gas phase species, are not well suited for investigations of much larger, solid phase species. Laboratory investigations of haze formation in planetary atmospheres therefore play a key role in improving our understanding of the formation and composition of haze particles. I will discuss a series of experiments aimed at improving our understanding of the physical and chemical properties of planetary atmospheric hazes on Titan and the early Earth.

UMD: Ackerson on Tuolumne quartz

2016 Geology Colloquium Series

Friday, October 14th 2016 at 3:00 pm
in PLS 1140

Mike Ackerson
Carnegie Institution for Science

Low-temperature crystallization of granites recorded in quartz from the Tuolumne Intrusive Suite

The granitic wet solidus is a curve in temperature, pressure and composition space below which silicate melt is not present. Based on the experimentally-determined solidus curves for granitic bulk compositions, it is often assumed that granitic mineral assemblages do not crystallize below ~650-700 °C. However, some experimental data indicate that hydrous peralkaline melts can exist in equilibrium with two feldspars and quartz to temperatures as low as 330 °C. It has yet to be demonstrated whether granitic melts exist in nature to such low temperatures. Ti-in-quartz thermobarometry of granitic rocks in the Tuolumne Intrusive Suite (TIS) of the Sierra Nevada Batholith indicates that quartz in the TIS records crystallization temperatures ~122-227 °C below the commonly accepted (traditional) granodiorite wet solidus. This observation agrees with two-feldspar thermometry of the TIS and demonstrates that for some granitic systems, the tradit! ional granitic wet solidus is not the low-temperature limit of granitic magmatism.