SAN FRANCISCO — The U.S. Geological Survey participates in the American Geophysical Union's fall meeting with hundreds of technical presentations. Below are some highlights of USGS science at AGU this year. Highlights about the technical sessions are presented in chronological order with session numbers, and room numbers in San Francisco's Moscone Convention Center (either Moscone South, MS, or Moscone West, MW). For more information, visit the AGU Fall meeting website.
News media representatives are invited to visit the USGS booth in the AGU Exhibit Hall. This is an easy place to connect with USGS data, publications, and information. Please contact Leslie Gordon to arrange for an interview with the USGS scientists.
News Conferences – Moscone West, Room 3000, Level 3
Dynamic Mars from Long–Term Observations
Tuesday, 12/10, 11:30 a.m. – Participating USGS Scientist Colin Dundas
Associated oral session with USGS Scientist Colin Dundas
Observations of Ice-Exposing Impacts on Mars over Three Mars Years
Wednesday, 12/11, 9:20 a.m., MW 2022/P31C-07
Titan as You've Never Seen it Before
Thursday, 12/12, 11:30 a.m. – Participating USGS Scientist Randolph Kirk
Associated oral session with USGS Scientist Randolph Kirk
Cassini RADAR Observes Titan’s Kraken Mare, The Largest Extraterrestrial Sea
Friday, 12/13, 11:05 a.m., MW 2007/P52B-04
Public Lecture --Sunday
Sunday, 12/8, 12:00 p.m. – MS 102
Free Public Lecture - Imagine an America without Los Angeles: Natural Hazards and the Complexity of Urban America
USGS Scientist: Lucy Jones
Lucy Jones will discuss how science can improve society’s resiliency to earthquakes. Free and open to the public.
Technical Sessions --Monday
Monday, 12/9, 8:00 a.m. – MS Poster Hall
Influence of Older Structure on Quaternary Faulting in Northeastern California
USGS Scientist: Vicki Langenheim
Geologically young faulting and volcanism may be influenced by a concealed crustal structure between Mt. Shasta and Lassen Peak. This structure is revealed by tiny perturbations in the Earth's gravity and magnetic fields caused by differences in rock density and magnetization.
Monday, 12/9, 8:15 a.m. – MW 2004
Deep Soil Carbon and Vulnerabilities to Anthropogenic Change
USGS Scientist: Jennifer Harden
Soils store large amounts of organic carbon (C), thus have helped regulate greenhouse gases and temperatures of the earth’s atmosphere. Land use change and rapid warming now influence the capacity for soils to actively store carbon. Scientists explore basic principles of soil formation and C cycling in order to understand how soils will respond to anthropogenic change.
Monday, 12/9, 1:40 p.m. – MS Poster Hall
Science For Decision-Makers: Climate Change Indicators For The North-Central California Coast And Ocean
USGS Scientist: Tom Suchanek
Ocean climate indicators were developed in a project based at NOAA’s Gulf of the Farallones National Marine Sanctuary for the North-central California coast and ocean, from Año Nuevo to Point Arena, including the Pacific coastline of the San Francisco Bay Area. These represent the first regional ocean climate indicators in the National Marine Sanctuary System. The indicators were developed in collaboration with over 50 regional research scientists and resource managers representing federal and state agencies, research universities and institutions, and non-governmental organizations.
Monday, 12/9,1:40 p.m. – MS Poster Hall
Comparison of Nutrient Sources in a Former Salt Pond Under Restoration
USGS Scientist: Brent Topping
Nutrient level fluctuations can disturb an ecosystem, and a key monitoring question during wetland restoration efforts is nutrient flux and transport. With the implementation of the South Bay Restoration Program in 2008, water quality in the Alviso Salt Ponds, California, has been monitored to document the effects of changing hydrologic connections among the ponds and the adjacent pond, slough and estuary. Ongoing research is shedding light on how bottom transport may be an important movement mechanism for both nutrients and toxicants in a rebuilding ecosystem.
Tuesday, 12/10, 9:15 a.m. – MW 3016
Multi-Scale Simulations of Past and Future Projections of Hydrology in Lake Tahoe Basin, California-Nevada
USGS Scientist: Richard Niswonger
Using a new-generation, linked surface- and groundwater-flow model, we examine impacts of climate changes and extremes in the Lake Tahoe basin. Climatic impacts are simulated in terms of water-availability and flood responses to selected climate-change projections and to an extreme ("ARkStorm") storm scenario and its resulting floods.
Tuesday, 12/10, 9:45 a.m. – MW 2003
Predicting Barrier Island Evolution Through Numerical-Model Scenarios
USGS Scientist: Nathaniel Plant
Prediction of barrier island evolution using numerical models can explain which processes, natural or human, are most important to long-term changes that affect future vulnerability to storms, sea-level rise, and human modification. Scientists will show numerical simulations of processes that transport sand along and across a barrier island during storms.
Tuesday, 12/10, 11:05 a.m. – MW 2000
A Global Perspective on Warmer Droughts as a Key Driver of Forest Disturbances and Tree Mortality
USGS Scientist: Craig Allen
Global warming and droughts are causing greater forest-water stress across large regions, and amplifying forest disturbances, particularly drought-induced tree mortality, wildfire, and insect outbreaks. Emerging global-scale patterns of drought- and heat-induced forest die-off are presented, including a newly updated map overview of documented die-off events from around the world, demonstrating the vulnerability of all major forest types to forest drought stress, even in typically wet environments.
Tuesday, 12/10, 1:40 p.m. – MS 103
Recent Microscopic Imager Results from Opportunity
USGS Scientist: Ken Herkenhoff
Exploration of Endeavour crater by the Mars Exploration Rover Opportunity continues, with the rover approaching more exposures of clay minerals detected from orbit; the latest Microscopic Imager results will be presented.
Tuesday, 12/10, 1:40 p.m. – MS Poster Hall
Magnetic Tides of Honolulu
USGS Scientists: Jeffrey Love, E. Joshua Rigler
Geomagnetic tides are time-periodic variations in the Earth’s magnetic field. Using almost a century of magnetic observatory data collected at the USGS in Honolulu Hawaii, we analyze magnetic tides caused by the relative motion and interaction of the Earth, Moon, and Sun, and the sunspot solar cycle.
Tuesday, 12/10, 1:40 p.m. – MS 103
Limits of Statistical Climate-fire Modeling: What Goes Up Must Come Down
USGS Scientist: Jeremy Littell
Climate affects wildfires, but “how” varies across ecosystems. Water balance (water surplus and drought) characterizes these effects, and scientists used it to project how fire could change under climate change. Will the whole West burn up? In some forests, it might appear so, but the whole story is more nuanced.
Tuesday, 12/10, 2:10 p.m. – MS 103
Different Climate–Fire Relationships on Forested and Non-Forested Landscapes in California
GC23G-03/ Oral presentation
USGS Scientist: Jon Keeley
Although wildfire activity is expected to increase due to global warming and other climate changes in the future, this study shows it is more complicated than a simple increase in fires with increased temperature. While climate will likely play an important role in determining fire regimes in the high elevation mountain forests, there is less evidence that it will alter fires at lower elevations. Future fires in California’s foothill and coastal environments will be affected by many global changes, particularly increases in human populations.
Tuesday, 12/10, 2:55 p.m. – MS 103
Can climate change increase fire severity independent of fire intensity?
USGS Scientist: Phillip van Mantgem
Regional warming may be linked to increasing fire size and frequency in forests of the western United States. Recent studies have also suggested that warming temperatures are correlated with increased fire severity (post-fire tree mortality), though the precise mechanism is unclear. Our research presents evidence that trees subject to environmental stress are more sensitive to subsequent fire damage. (see related news: http://www.usgs.gov/newsroom/article.asp?ID=3649)
Tuesday, 12/10, 3:25 p.m. – MW 3002
Are Large-scale Manipulations of Streamflow for Ecological Outcomes Effective Either as Experiments or Management Actions?
USGS Scientist: Chris Konrad
Water managers increasingly address ecological sustainability as part of dam operations. Dam releases for ecological outcomes have been practiced for over half a century to improve ecological conditions in rivers and estuaries. A review of more than 100 large-scale flow experiments evaluates their effectiveness for learning how to achieve sustainable water management.
Wednesday, 12/11, 8:00 a.m. – MS Poster Hall
Surprise and Opportunity for Learning in Grand Canyon: The Glen Canyon Dam Adaptive Management Program
USGS Scientist: Ted Melis
Flow experiments from Glen Canyon Dam since 1990, have informed federal managers trying to mitigate peak water flow impacts on Colorado River resources. Results were not predicted, but were "surprise" learning opportunities for adaptive river managers. Major uncertainties remain about the influence of global warming on the river’s native fish and beaches.
Wednesday, 12/11, 11:20 a.m. – MS 307
Missing Great Earthquakes
USGS Scientist: Susan Hough
The past decade has witnessed an apparent bumper crop of great earthquakes, with a total of six events above M8.5. Best available historical catalogs reveal only seven M≥8.5 earthquakes during the entire 19th century. Although the average long-term rate of global great earthquakes remains uncertain, one can show that great earthquakes are missing and/or estimated in best-available historical catalogs. Since the largest known earthquakes in many regions occurred before seismometers were developed around 1900, some of our estimates of largest possible magnitudes are likely too low. This suggests that so-called black swan events like the 2011 Tohoku, Japan, earthquake, while still not commonplace events, are not such rare beasts after all.
Wednesday, 12/11, 11:20 a.m. – MW 3003
An Integrated, Indicator Framework for Assessing Large-Scale Variations and Change in Seasonal Timing and Phenology
USGS Scientist: Julio Betancourt
As part of the National Climate Assessment's Indicator System, the Seasonality and Phenology Indicators Technical Team proposed a framework for tracking variations and trends in seasonal timing of surface climate, snow and ice, vegetation green-up and flammability, and bird migration across the U.S. These national indicators are measured by day-of-year, number of days, or latitude of observation at a given date.
Wednesday, 12/11, 1:40 p.m. – MS Poster Hall
Tracking Hydrothermal Feature Changes in Response to Seismicity and Deformation at Mud Volcano Thermal Area, Yellowstone
USGS Scientist: Angie Diefenbach
Mapping surficial change over 50 years at Mud Volcano thermal area in Yellowstone using readily accessible archives of aerial photographs from several federal agencies, gives scientists a better understanding of the links between seismicity and deformation episodes to increased heat and gas emissions at thermal areas.
Wednesday, 12/11, 1:55 p.m. – MW 3009
Influences on the Morphologic Response to Hurricane Sandy: Fire Island, NY
USGS Scientist: Cheryl Hapke
Hurricane Sandy fundamentally altered the geomorphology of Fire Island, NY. Changes included severe beach erosion, razing of the dunes, extensive overwash and breaching of the island. The response during Sandy varied considerably along the island and appears to be largely controlled by the local geology (associated poster session Monday, 12/9 at 1:40 p.m. – MS Poster Hall).
Wednesday, 12/11, 3:10 p.m. – MW 3009
Sandy-related Morphologic Changes in Barnegat Bay, NJ
USGS Scientist: Jennifer Miselis
Estuaries are some of the most productive habitats in the world. Biological, chemical, and physical estuarine processes are influenced by changes in depth and sediment composition, but storm-related changes are rarely measured. Our study integrates airborne and boat-based sensors and sampling to understand estuarine changes caused by Superstorm Sandy.
Thursday, 12/12, 8:00 a.m. – MS Poster Hall
Fog as an ecosystem service in northern California
USGS Scientist: Alicia Torregrosa
Humans can greatly benefit from temperature cooling derived from coastal fog such as reducing the number of hospital visits/emergency response requests from heat stress-vulnerable population sectors or decreased energy consumption during periods when summer maximum temperatures are lower than normal. The thermal relief provided by summertime fog and low clouds is equivalent in magnitude to the temperature increase projected by the driest and hottest of regional downscaled climate models using the A2 (“worst”) IPCC scenario. Extrapolating these thermal calculations can facilitate future quantifications of the ecosystem service provided by summertime low clouds and fog.
Thursday, 12/12, 8:00 a.m. – MS Poster Hall
SAFRR Tsunami Scenario: Economic Impacts and Resilience
USGS Scientists: Anne Wein
The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an M9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. We provide an overview of the likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California associated with the tsunami scenario. Scenario users are those who must make mitigation decisions before, response decisions during, and recovery decisions after future tsunamis.
(associated oral presentations on Friday, 12/13 starting at 5:30 p.m. – MS 309)
Thursday, 12/12, 8:00 a.m. – MS Poster Hall
Multi-Temporal Harmonization of Independent Land-Use/Land-Cover Datasets for the Conterminous United States
USGS Scientist: Chris Soulard
USGS Land Change research aims to extend LULC change monitoring beyond 1973-2000 to more recent dates, without resource-intensive manual interpretation. We leveraged a range of existing LULC products and improved LULC classification by identifying agreement between datasets. This process, termed harmonization, has proven to be a cost efficient way to create reliable LULC maps.
Thursday, 12/12, 8:00 a.m. – MS Poster Hall
Megasplash at Lake Tahoe
USGS Scientist: Jim Moore, Richard Schweickert (Univ. of Nevada)
One of the largest landslides on the continent occurred in Lake Tahoe 12,000 to 21,000 years ago. Backwash from the gigantic splash caused by the 2.5 cubic-mile landslide formed major tsunamis. This backwash was equivalent to 15 major rivers flowing into the lake at the same time, and would have decimated life in the splash zone surrounding the lake.
Thursday, 12/12, 8:45 a.m. – MW 3001
Integrated Climate/Land Use/Hydrological Change Scenarios for Assessing Threats to Ecosystem Services on California Rangelands
USGS Scientist: Kristin Byrd
Scientists have developed integrated climate/land use/hydrological change scenarios for assessing threats to ecosystem services on California rangelands. Model outputs quantify the impact of urbanization on water supply and show the importance of soil storage capacity. Scenarios have applications for climate-smart conservation and land use planning.
Thursday, 12/12, 9:15 a.m. – MS 307
Understanding the Largest Deep Earthquake Ever Recorded
USGS Scientist: Robert Graves, Shengji Wei (Caltech)
In May 2013 a M8.3 earthquake ruptured beneath the Sea of Okhotsk at a depth of 610 kilometers, far below the Earth's crust. The entire earthquake sequence took just 30 seconds with energy released in four major shocks. This suggests that deep earthquakes are more efficient in dissipating stress than shallow earthquakes.
Thursday, 12/12, 11:20 a.m. – MW 3007
High Resolution Space-Time Analysis of Ice Motion at a Rapidly Retreating Tidewater Glacier
USGS Scientist: Shad O’Neel
Rapid changes to rates of sea level rise are forced in large part by tidewater glacier dynamics. With unprecedented detail, we analyze discharge from Alaska’s Columbia Glacier supporting other lines of evidence that the retreat has peaked and is now declining, suggesting regional ice mass loss rates may also decrease.
Thursday, 12/12, 3:25 p.m. – MS 308
Detecting Deep Crustal Magma Movement: Exploring Linkages Between Increased Gas Emission, Deep Seismicity, and Deformation Prior to Recent Volcanic Activity
USGS Scientist: Cynthia Werner
In 2003, deep long-period earthquakes, CO2 emissions, and surface uplift were described as three ‘promising indicators’ of deep magmatic processes. Now, ten years later, new data suggests that indeed that combination of very subtle changes in these parameters can help understand and predict changes in volcanic activity months in advance.
Thursday, 12/12, 5:00 p.m. – MS 307
Megacity Megaquakes: Two Near Misses, and the Clues they Leave for Earthquake Interaction
USGS Scientist: Ross Stein
Two recent mega-earthquakes, a M8.8 earthquake off the Chilean coast and a M9.0 earthquake off the coast of Japan, resulted in a large number of fatalities. Even though the capital cities of Santiago and Tokyo escaped severe damage, the rate of lesser shocks beneath each city jumped by a factor of about 10 following each megaquake. What does this portend for the likelihood of future large earthquakes? Are these really aftershocks, and are large shocks more probable now than before the mega-earthquakes?
Thursday, 12/12, 5:30 p.m. – MS 305
Crowd-Sourcing for Earthquake Monitoring and Rapid Response
USGS Scientist: Sarah Minson
Earthquake early warning systems are being implemented in select locations. Expansion to high-risk regions lacking seismic infrastructure, however, is cost-limited. Scientists demonstrate that a stand-alone system comprising cell-phone quality GPS stations is inexpensive enough to be implemented globally and accurate enough to provide early warning of large earthquakes and tsunami.
Thursday, 12/12, 5:45 p.m. – MS 309
Six Large Tsunamis in the Past ~1700 years at Stardust Bay, Sedanka Island, Alaska
USGS Scientist: Robert Witter
On a small island facing the Aleutian-Alaska subduction zone, the 1957 Andreanof Islands tsunami deposited beach sand and stranded drift logs 18 meters above sea level. Five older sand sheets suggest great earthquakes along this part of the Aleutian megathrust generate Pacific-wide tsunamis on average every 325 years. Intriguingly, the age of the predecessor of the 1957 tsunami overlaps the time of unusual marine flooding on Kaua'i about 400 years ago.
Friday, 12/13, 8:00 a.m. – MS Poster Hall
Recent Applications of Continental-Scale Phenology Data for Science, Conservation, and Resource Management
USGS Scientist: Jake Weltzin
Professional and “citizen” scientists are contributing data on seasonal plant and animal activity across the United States – as part of a national project called Nature’s Notebook – to inform science and natural resource management. Featured applications include a national index of Spring and tools to support detection and eradication of invasive plants.
Friday, 12/13, 11:05 a.m. – MS 309
Community Vulnerability to Tsunami Threats in the U.S. Pacific Northwest
USGS Scientist: Nathan Wood
Coastal communities in northern California, Oregon, and Washington are classified based on similar characteristics of vulnerability to tsunamis associated with Cascadia subduction zone earthquakes. Research focuses on the number and type of at-risk individuals in hazard zones, including estimates of needed evacuation time. Results can be used to prioritize risk-reduction efforts that address common issues across multiple communities.
Friday, 12/13, 2:10 p.m. – MS 307
The Effect of Porosity on Fault Slip Mechanisms at East Pacific Rise Transform Faults: Insight From Observations and Models at the Gofar Fault
USGS Scientist: Emily Roland
East Pacific Rise transform (strike-slip) faults demonstrate significant variability along their length in their ability to generate large earthquakes. Using observations and models, scientists consider how changes in fault zone material properties, specifically porosity of fault zone rocks and pore fluid pressure, may influence rupture segmentation.
Friday, 12/12, 5:30 p.m. – MS 309
The SAFRR Tsunami Scenario: Improving Resilience for California from a Plausible M9 Earthquake near the Alaska Peninsula
USGS Scientist: Stephanie Ross
The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an M9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. The scenario includes the likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California, providing the basis for improving preparedness, mitigation, and continuity planning for tsunamis, which can reduce damage and economic impacts and enhance recovery efforts.
Friday, 12/12, 5:45 p.m. – MS 309
Environmental and Environmental-Health Implications of the USGS SAFRR California Tsunami Scenario
USGS Scientist: Geoffrey Plumlee
The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an M9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. Environmental impacts from contamination and potential for human exposures to contaminants and hazardous materials, are an underappreciated hazard from tsunamis. Inundation-related damages to major ports, boat yards, and many marinas could release complex debris, crude oil, various fuel types, other petroleum products, some liquid bulk cargo and dry bulk cargo, and diverse other pollutants into nearby coastal marine environments and onshore in the inundation zone.