NOAA-Sponsored Scientists First to Map Offshore San Andreas Fault and Associated Ecosystems

Dr. Chris Goldfinger, project PI, watches the multibeam screen as data returns in near-real time. Bathymetric and backscatter data obtained from multibeam sonar are used to determine seafloor depth as well as indicators of the type of sediment (hard or soft bottom) that is below. Image courtesy of San Andreas Fault 2010 Expedition, NOAA-OER.

For the first time, scientists are using advanced technology and an innovative vessel to study, image, and map the unexplored offshore Northern San Andreas Fault from north of San Francisco to its termination at the junction of three tectonic plates off Mendocino, Calif.

The team includes scientists from NOAA’s National Marine Fisheries Service, Oregon State University, the California Seafloor Mapping Program, the U.S. Geological Survey and Woods Hole Oceanographic Institution. The expedition which concludes Sunday is sponsored by NOAA’s Office of Ocean Exploration and Research.

While the fault on land is obscured by erosion, vegetation and urbanization in many places, scientists expect the subsea portion of the fault to include deep rifts and high walls, along with areas supporting animal life. The expedition team is using high-resolution sonar mapping, subsurface seismic data and imaging with digital cameras for the first-ever three-dimensional bathymetric-structural map that will model the undersea Northern San Andreas Fault and its structure. Little is known about the offshore fault due to perennial bad weather that has limited scientific investigations.

“By relating this 3-D model with ongoing studies of the ancient record of seismic activity in this volatile area, scientists may better understand past earthquakes — in part because fault exposure on land is poor, and the sedimentary record of the northern California offshore fault indicates a rich history of past earthquakes,” said Chris Goldfinger, co-principal investigator and marine geologist and geophysicist at Oregon State University in Corvallis, Ore. “The model will also benefit geodetic studies of the buildup of energy to help better understand the potential for earthquakes.”

More than a century after the 1906 Great San Francisco Earthquake, the science team is also exploring the fault for lessons associated with the intertwined relationships between major earthquakes and biological diversity. Evidence shows that active fluid and gas venting along fast-moving tectonic systems, such as the San Andreas Fault, create and recreate productive, unique and unexplored ecosystems.

“This is a tectonically and chemically active area,” said Waldo Wakefield, co-principal investigator and a research fisheries biologist at NOAA’s Northwest Fisheries Science Center in Newport, Ore. “I am looking for abrupt topographic features as well as vents or seeps that support chemosynthetic life — life that extracts its energy needs from dissolved gasses in the water. I’m also looking at sonar maps of the water column and images of the seafloor for communities of life.”

This image shows the subsurface San Andreas Fault, approximately eight miles offshore Fort Bragg, Calif. The fault scarp, or step-like feature is 30-50 meters high. The depressions shown next to it, called "sag ponds" on land, result from small changes in the trend of the fault. (Credit: Image courtesy of San Andreas Fault 2010 Expedition, NOAA-OER).A variety of sensors and systems are being used to help locate marine life including a NOAA autonomous underwater vehicle (AUV) named ‘Lucille.’ Elizabeth Clarke, a NOAA fisheries scientist, is coordinating Lucille’s operations and obtaining photographic information about fauna associated with the fault. The AUV and its sensors can dive to nearly one mile (1,500 meters), but depths associated with this expedition will range between approximately 230 to 1100 feet (70 to 350 meters).

Early in the expedition, scientists collected bathymetric and subsurface seismic reflection data to guide them to specific areas of interest for follow-on and more detailed operations. The AUV’s high-definition cameras are obtaining multiple images to be stitched into “photo mosaics” showing detailed fault structure and animal life.

The first part of the expedition is operating from Research Vessel Derek M. Baylis, a “green” research vessel primarily powered by sail and owned by Sealife Conservation, a nonprofit organization. The expedition will track the carbon footprint of the 65-foot energy efficient Baylis and compare results to conventional vessels.

AUV operations are being conducted aboard the Research Vessel Pacific Storm, operated by Oregon State University’s Marine Mammal Institute. The ship and AUV team joined the expedition offshore of Fort Bragg on Sept. 25.

As the expedition progresses, NOAA’s Ocean Explorer website features maps and images of the fault and associated ecosystems, logs from scientists at sea, and lesson plans that align with National Science Education Standards at three grade levels.

NOAA’s Office of Exploration and Research uses state-of-the-art technologies to explore the Earth’s largely unknown ocean in all its dimensions for the purpose of discovery and the advancement of knowledge.

NOAA’s mission is to understand and predict changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Visit us on Facebook at

[Source: NOAA press release]

RS and GIS-based Temporal-spatial Variation and Multi-factor Spatial Analysis on Nonpoint Source Pollution

18th International Conference on Geoinformatics, 18-20 June 2010, Beijing, China

Shan, Nan; Ruan, Xiaohong; and Ao, Jing

“Nonpoint source (NPS) pollution has become one of the biggest challenges in maintaining water quality and aquatic ecosystems. However, the impacts of topography, land use change, human activities, precipitation etc., make the modeling and control of NPS pollution in temporal and spatial scales difficult. In recent years, the rapid development of Remote Sensing (RS) and Geographic Information System (GIS) technologies provide a new research method to investigate into NPS pollution. Since the construction of the Three Gorges Reservoir, the water flow of the reservoir slows down and the capability of water body self-purification is decreasing, consequently water quality of this area is getting worse due to the NPS pollution. In this paper, a methodology which based on RS and GIS for evaluating the NPS pollution was described and tested on the Ruxi River basin, which is a branch of Yangtze River basin in Three Gorges Project area, Southwestern China. Multi-temporal remote sensing images were used to analyze the variety of long-term land use change. GIS was used to characterize the sub-basins throughout the watershed for changes in land use and analyze multi-factor spatial relationship in NPS pollution. The Soil and Water Assessment Tool (SWAT) and a series of water quality data in the field were used to simulate the temporal-spatial features of total nitrogen (TN) and total phosphorus (TP). Research results indicate that the impacts of anthropic activities on landscape are intensive to NPS pollution. There is a strong relationship between slope, land cover, distance to the stream channel and NPS pollution.”

Towards Meaningful URIs for Linked Sensor Data

Proceedings of the Workshop “Towards Digital Earth: Search, Discover and Share Geospatial Data 2010” at Future Internet Symposium, Berlin, Germany, September 20, 2010

Krzysztof Janowicz, Arne Bröring, Christoph Stasch, Thomas Everding

“Sensor data is stored and published using OGC’s Observation & Measurement specifications as underlying data model. With the advent of volunteered geographic information and the Semantic Sensor Web, work on an ontological, i.e. conceptual, model gains importance within the Sensor Web Enablement community. In contrast to a data model, an ontological approach abstracts from implementation details by focusing on modeling the real world from the perspective of a particular domain or application and, hence, restricts the interpretation of the used terminology towards their intended meaning. The shift to linked sensor data, however, requires yet another perspective. Two challenges have to be addressed, (i) how to refer to changing and frequently updated data sets such as stored in Sensor Observation Services using Uniform Resource Identifiers, and (ii) how to establish meaningful links between those data sets, i.e., observations, sensors, features of interest, observed properties, and further participants in the measurement process. In this short paper we focus on the problem of assigning meaningful URIs.”