UMD Geology: Titan’s organic aerosols

2016 University of Maryland Geology Dept. Colloquium Series

Friday, September 23rd 2016 at 3:00 pm
in PLS 1140

Melissa Trainer

Insights on Titan’s organic aerosol formation from the laboratory

Saturn’s moon Titan is enshrouded with a thick haze that is the product of the extensive organic chemistry that takes place in Titan’s N2/CH4 atmosphere. The organic aerosol that comprises the haze has been studied extensively through observation and experimental simulations, yet the exact nature of the composition or formation mechanisms are still not known. Laboratory studies in our group have explored the optical, chemical, and isotopic properties of photochemical Titan aerosol analogs to provide insight on the major components and formation mechanism that may influence aerosol production on Titan. I will review our findings and discuss implications for improved understanding of observations of Titan’s haze as well as the chemical cycle of CH4 and trace atmospheric species.

USGS Mendenhall seminar: sea-level rise threats to endangered species

Mendenhall Postdoctoral Research Seminar

Sara Zeigler, USGS – Woods Hole, MA

When: Wednesday, September 14, 2016 – 12 Noon

Where: Via WebEx and National Center, Room 4C315


A multi-disciplinary approach for understanding sea-level rise threats to endangered species (or “Ecologists + Geologists = cool science”)

Managers within DOI and state agencies as well as private conservation organizations are tasked with protecting species reliant on highly dynamic coastal ecosystems – landforms effected by sea-level rise, changing storm regimes, and increasing infrastructure. A multi-disciplinary and multi-stakeholder data collection and analysis approach that can be used to inform conservation and management of species like piping plovers (Charadrius melodus) in these dynamic coastal environments will be described. This approach required collaboration across several DOI agencies and USGS science centers. The speaker will describe a smartphone application developed for data collection (‘iPlover’), Bayesian network models constructed for data analysis, and example applications of the approach for mapping piping plover habitat suitability at sites along the U.S. Atlantic coast. The applications of this approach are broad and will facilitate and increase cooperation among scientists and managers in the efficient conservation of endangered species.

WebEx Info

Topic: Mendenhall Presentation by Dr. Sara Zeigle
Date: Wednesday, September 14, 2016
Time: 11:30 am, Eastern Daylight Time (New York, GMT-04:00)
Meeting number: 710 957 575
Meeting password: (This meeting does not require a password.)
Host Key: 385542

JOIN WEBEX MEETING Meeting number: 710 957 575 Host key: 385542 JOIN BY PHONE National Center in Reston, VA Dial In: x4848 DOI Dial In Number: 703-648-4848 Non-DOI Toll Free Dial In Number: 1-855-547-8255* Security Code: 91930 followed by the # sign

For help with WebEx:
– Visit, click USGS Help (on left)
– WebEx software questions: 1-866-569-3239 (24/7)
– USGS account questions: e-mail

To check whether you have the appropriate players installed for UCF (Universal Communications Format) rich media files, go to

PGS: Michael Ryan on magma physics of Hawaii

Welcome back from summer break!  Please join us for the September 15, 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

Dr. Michael Ryan, The Magma Physics Project, Hilo, Hawai’i

“Rock-, mineral-, and melt-physics and magma neutral buoyancy in Hawai’i”

Talk Abstract:

Compressional and shear wave velocities in the mafic and ultra-mafic rocks that make up Hawaiian volcanoes and their crustal and upper mantle underpinnings have been combined with additional petrophysical properties to understand the mechanical rationale for the existence and long-term evolution of subcaldera magma reservoirs in active volcanic centers such as Kilauea and Mauna Loa. These additional properties include single crystal elastic constants, high temperature elastic moduli,  thermal expansion coefficients, the pressure-dependence of crack and joint closure, and the P-T dependence of in-situ rock, melt and magma densities. When the data is combined with long-term geodetic, seismic, geologic and 3-D modelling data, compelling and very durable existence and evolutionary criteria have been discovered for these magma reservoirs. Regions of neutral buoyancy are produced by the crossover in the in-situ densities of magmatic fluids and the rocks surrounding subcaldera  magma reservoirs and rift systems. Beneath this region, magma parcels ascend driven by positive buoyancy forces, whereas above it, they decend under the influence of negative buoyancy. Within Mauna Loa and Kilauea, the region of neutral buoyancy is coincident with the location of the subcaldera magma reservoir. Based on laboratory and field measurements of Vp and Vs, the compression of the rock column beneath these volcanoes is divisable into two fields: an upper field of fracture, macropore, micropore and mineral compression (0-9 km depth) and a deeper field of mineral compression only (9 km and deeper). This compression—or contraction—profile, is inherently non-linear: the upper (non-linear) portion reflecting the greater bulk compressibility of rock porosity+aqueous fluids, and the lower (linear) portion reflecting aggregate mineral compressibilities. Velocity-density systematics connect the rock data with the melt and magma data—revealing the in-situ density crossover in the 2-7 km depth range for both these volcanoes: the region of neutral buoyancy. The region of neutral buoyancy combined with the contraction profile that induces it thus provides for the long-term stability (the existence) of subcaldera magma reservoirs and their rift systems. As Hawaiian volcanoes age and evolve, they carry their contraction profile and region of neutral buoyancy upward with them. Thus the evolutionary progression from seamount (Loihi) to subaerial immature shield (Kilauea) to mature volcano (Mauna Loa), is one characterized by the progressive elevation of the summit reservoir complex and rift zones—a process that leaves beneath a wake of high velocity mafic and ultramafic rocks within the core region of the shield. For Hawaiian rift systems, the lateral magma injection process follows the horizon of neutral buoyancy, where countryrock and magma densities are equal. This is the region of preferred dike formation and of magma residence and mixing with the accompanying migrating swarms of microseismicity in the 2-4 km depth interval. Beyond Hawaii, the neutral buoyancy systematics also apply to the Earth’s mid-ocean ridge system, to Icelandic central volcanoes, and to island arc and continental arc volcanoes, among others.


Speaker Bio:

Michael Ryan has 42 years experience in physical volcanology. He has worked on active volcanoes in Hawai’i (Kilauea, Mauna Loa), the high Cascades (Mt. St. Helens), Iceland (Krafla, Askja) and Japan (Sakurajima). He has studied the interiors of ancient dissected volcanoes across the U.S., Iceland, and Japan. He has a B. Sci. and M. Sci. in geology from Michigan State University, and a Ph. D. in geochemistry & mineralogy from the Pennsylvania State University with parallel work in engineering mechanics, ceramic science, and petroleum & natural gas engineering. His post-doctoral work was in the Dept. of Mineral Sciences of the Smithsonian Institution of Washington, D.C. He has taught graduate courses in geology and geophysics at the University of Hawai’i-Manoa where he also conducted research on active volcanism. He conducted research for 30 years with the U.S. Geological Survey and is now affiliated with the Magma Physics Project in Hilo, Hawai’i. His emphasis is on the pathways and processes that regulate the migration of magma from Earth’s mantle through the crust and into the interiors of active volcanoes.

Paleontological Society of Washington: Fraser on climatic and biotic interchange

The Paleontological Society of Washington

7:00 pm, Wednesday, September 21

National Museum of Natural History, Constitutional Ave. entrance

The roles of climate and biotic interchange in the assembly of mammal communities

Danielle Fraser

Smithsonian National Museum of Natural History

Climate, speciation, extinction, and invasion are thought to structure patterns of species diversity. I use phylogenetic community assembly metrics to understand mammal responses to long-term climate and faunal changes during the Cenozoic (66 Ma – present). My research is a critical step in answering “What factors have led to the emergence of communities as we know them today?” and in generating predictions for the impact of human-driven extinction on modern community assembly.

Non-Smithsonian visitors will be escorted 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 Constitutional Ave. entrance of the NMNH at 5:00 and walk to the restaurant as a group.

GSW 1509: EarthScope evening extravaganza

The 1509th meeting of the Society will be on
Wednesday, September 14, 2016

Vedran Lekic, The University of Maryland at College Park:
Peering into the Earth with an EarthScope
10 minutes

Scott Burdick, The University of Maryland at College Park:
Subducted slabs and mantle plumes beneath North America from body wave tomography
25 minutes

Tolulope Olugboji, The University of Maryland at College Park:
Mapping the crustal structure of the conterminous USA using surface waves.
25 minutes

This will be the first meeting for the fall.

Refreshments at 7:30 PM; Formal program at 8:00 PM
John Wesley Powell Auditorium, 2170 Florida Avenue NW, Washington, DC

Ocean Film Showcase @ NMNH Sept. 10

The National Museum of Natural History, the U.S. Department of State, the Jackson Hole Wildlife Film Festival, the D.C. Environmental Film Festival, and BLUE Ocean Film Festival would like to invite you to the Our Ocean Film Showcase at the National Museum of Natural History on September 10th.

Organized in conjunction with the international Our Ocean conference that will be hosted by Secretary John Kerry in Washington in September, this showcase will feature a curated selection of ocean-related documentary films and include panel discussions with prominent figures including National Geographic Explorers-in-Residence Dr. Sylvia Earle and Dr. Enric Sala, and State Department’s Under Secretary for Economic Growth, Energy, and the Environment Cathy Novelli. The showcase aims to look at the state of our ocean environment.

Please find the RSVP below. We kindly ask that you share this with your distribution networks.

Our Ocean Film Showcase – Film Festival and Discussions

September 10, All-Day 
Baird Auditorium, Ground Floor
National Museum of Natural History

Life on Earth depends on the ocean.  A healthy ocean is central to human wellbeing.  The ocean feeds billions of people, employs millions of workers, and generates trillions of dollars in the world economy.

Yet, as vast as our ocean and its resources are, they are not infinite.  And today the ocean is under tremendous pressure from human activity – including unsustainable and illegal fishing, marine pollution, and climate-related impacts.

The Our Ocean Film Showcase will feature a curated selection of thought-provoking ocean documentary films and include panel discussions with filmmakers and leading figures who are working to better understand how to sustain a healthy ocean.

RSVP for this event»


Geology of Alexandria, VA field trip

Geologic Field Trip – Alexandria, Virginia and Vicinity


Date: Monday, October 10, 2016, 9 AM – ?

Leader: Tony Fleming, author of the 2016 Geologic Atlas of Alexandria, VA (

Who: geologists, geotechnical engineers, building and planning staff, environmental professionals

Meeting Place: Ford Nature Center, 5750 Sanger Avenue, Alexandria, VA 22311


Alexandria features a strongly dissected fall line landscape with some of the most varied geology and topography in the Potomac Valley, ranging from complexly deformed crystalline bedrock of the Piedmont in the west to many steep, active hillsides developed on the eastward-thickening wedge of early Cretaceous Potomac Formation further east, along with a host of upland and lowland river terraces, debris fans, and associated hillside deposits. This trip will highlight a variety of geologic features and scientific problems of local and regional interest to geologists and geotechnical engineers working in the greater mid-Atlantic region.


Stops and topics featured on the trip include:

– Structure of the Paleozoic bedrock and the nature of the regionally significant erosional unconformity on the bedrock surface, which appears to have unusually high local relief at places in the City.


– The character, facies relations, deformation, hydrogeology, and geotechnical properties of the early Cretaceous Potomac Formation as seen at its updip end. The Potomac Formation is well exposed throughout the highlands in the western two thirds of the city and will be a major focus of the trip because of its geomorphic, hydrogeologic and geotechnical significance. We will see good examples of the informal members defined in the atlas, as well as the major aquifer system it hosts, and for which western Alexandria is part of the regional recharge area.


– Nature and evolution of the landscape from the late Tertiary through Recent. The City contains more and larger river terraces than most other parts of northern Virginia, including several widespread “upland” gravels whose ages remain poorly defined yet are of fundamental importance to our understanding of issues like seismic risk and incision history of the landscape;


– Tectonics, faults, and modern seismic hazards. Ample evidence indicates that comparatively young fault zones project into the City from both the north (DC/Rock Creek fault system) and the south (Stafford fault system), but defining and mapping their locations with a reasonable degree of precision in this heavily urbanized area is a real challenge. We will visit some of the localities where faults have been documented or are strongly suspected, and revisit subsurface data presented in the atlas for some of these “suspect” places.


Alexandria contains all of these features within a compact area, which will greatly reduce travel time between stops and allow for maximum time in the field. In addition to illustrating the strata and features depicted in the city atlas, the intent of the trip is to stimulate lively discussion among this group of regional experts and professionals. I look forward to your participation.


Please contact the field trip leader ( if you plan to attend or have any questions, and feel free to forward this announcement to colleagues who may be interested in the outing.