ISGS - September 2007 Activity Highlights
ISGS - Home Page of the Illinois State Geological Survey
Data from the Geospatial Data Clearinghouse
Illinois Clearinghouse: Celebrating Ten Years of Data Distribution
The Illinois Natural Resources Geospatial Data Clearinghouse (Illinois Clearinghouse) was first brought on-line July 1997. The Illinois Clearinghouse serves as a gateway to Geographic Information Systems (GIS) and remote sensing data for Illinois and provides access to topographic maps, framework orthoimagery collections, historic aerial photography, infrastructure and natural resource data, and ArcIMS interactive Map Services. The clearinghouse is a formal National Spatial Data Infrastructure (NSDI) node (one of more than 300 worldwide) that is compliant with federal Geospatial One-Stop standards.
The Illinois Clearinghouse receives enthusiastic support from the Illinois GIS user community. Last year, 140,000 visitors accessed over 2 million Illinois Clearinghouse Web pages. During its 10-year history, customers of the Illinois Clearinghouse have enjoyed on-demand access to more than 27,800 data files and 18,300 aerial photos totaling over 35 terabytes of information free of charge. The project to enable access to 2005 digital orthoimagery collections prompted requests from Google, Mapquest, Microsoft Earth, Navteq, the Nature Conservancy, the National Weather Service, and FutureGen partner agency representatives. A Web search for the key words "Illinois" and "GIS" offers the Illinois Clearinghouse as the first Web site returned by Google, Yahoo, AOL, and Ask.com. Additionally, GIS data downloads have become part of the curriculum for geography and GIS classes at several Illinois universities.
Together with the main Illinois State Geological Survey (ISGS) home page, ISGS mapping services that provide easy access to significant data holdings (such as oil and gas well data), and an e-commerce site that will be launched soon, The Illinois Clearinghouse represents one facet of the Survey's business presence on the Internet. The Illinois Clearinghouse continues to receive broad recognition from many people in Illinois, the Midwest, and the nation. To date, over $1.3 million has been dedicated to the expansion and upkeep of the Illinois Clearinghouse. Financial support to enable on-line access to Illinois data has been sustained through 40 separate grants, contracts, and student internships from Illinois state and county agencies, universities, and federal programs. Hosted by the ISGS, the Illinois Natural Resources Geospatial Data Clearinghouse can be found on-line at www.isgs.illinois.edu/nsdihome. (Contact: S. Beaverson)
Searching for Buried Steam Boats
On the evening of April 25,1840, the Bedford, a relatively small side wheel steamboat, was descending the Missouri River near its mouth, bound for St Louis, when she struck a snag and sank in less than five minutes in deep water. Over the ensuing decades, the Missouri River channel has shifted to the south so much that the site of the Bedford's wreck is now beneath dry land. During June 2007, under the auspices of the Army Corps of Engineers, St. Louis District, an Illinois State Geological Survey geophysicist conducted a magnetometer survey looking for the Bedford and two other wrecks. The iron boilers and engines from the old steamboats should produce a large magnetic anomaly even if the wrecks are buried 30 to 40 feet below ground. After a week of trekking through corn fields, sloughs, and cottonwood saplings with a magnetometer and GPS mounted on his back, the geologist located a telltale anomaly not far from the reported location of the Bedford wreck. Unfortunately, the other wreck sites could not be located. The large magnetic anomaly was found in a swale on the "back side" of what once was Mobile Island. This swale could have been a short cut channel near the mouth of the Missouri. The magnetic anomaly is consistent with 8 to 12 tons of iron buried at a depth of 35 to 40 feet. The site is located within Missouri Department of Natural Resources (DNR) Confluence Point State Park. Archeologists from the Missouri DNR are developing a plan to collect drill core from the site to determine whether the Bedford has finally been found. (Contact: T. Larson)
Addressing Geologic Hazards through International Ocean Drilling Program Workshop
The Illinois State Geological Survey contributes to the International Ocean Drilling Geo Hazard Program (IODP) by developing the Coastal Zone Geo Hazard Geophysical Observation System based on off shore drilling platforms. As was dramatically shown by the Sumatra earthquake and associated tsunami of late 2004, the oceans are the source of some of the most severe geologic hazards. Large tsunamigenic earthquakes tend to occur several times per century, commonly near coastal areas, with devastating impacts on communities and coastlines both near to and far from the source. Smaller earthquakes also can generate significant tsunamis, often much larger than predicted by the earthquake magnitudes. Global examples are well known and include seismically active plate boundaries of all types. Oceanic hazards are generated in many other settings as well. These settings include passive margins in which rapid sedimentation, fluid overpressure, or gas hydrate dissociation can cause slope failure. Explosive eruptions and sudden flank deformation on coastal or island volcanoes can induce sector collapse and catastrophic landslides and have the potential to generate devastating tsunami and related coastal damage.
The mechanisms and controls on tsunamigenic deformation are still incompletely understood, as are their distribution in time and space. Because of their oceanic setting, tsunamigenic events are often preserved in the marine sedimentary record. Thus, ocean drilling provides several new opportunities to extract and read this geologic record and to monitor physical and chemical processes and changes in material properties associated with dangerous geologic phenomena. Developing a sound scientific understanding of the geological and physical processes underlying these hazards is crucial to efforts to evaluate their distributions, to produce predictive models, and to mitigate their risks. Presently, the characterization and understanding of the causes and consequences of oceanic geologic hazards is an under realized element of the IODP Initial Science Plan.
The workshop, which convened in Portland, Oregon, August 26 to 30, 2007, was designed to establish the current state of community knowledge and activity in the area of submarine geologic hazards and to address a series of focused questions. In particular, investigations of geologic hazards through scientific ocean drilling still face many obstacles. The understanding of the necessary conditions and triggers for catastrophic geologic events (e.g., landslides, earthquakes, and tsunami) is incomplete, and instruments for making in situ or remote measurements of the geotechnical and other material properties of the rocks and sediments involved are limited. Moreover, there is a need to define tractable scientific questions and to design realistic science and engineering plans that can actually answer them. Key goals of the workshop were to define outstanding research questions that can be addressed through scientific ocean drilling, establish scientific priorities, identify potential drilling targets, evaluate existing technologies and scientific approaches, and formulate strategies to overcome anticipated scientific and engineering challenges. The workshop enhanced international collaborations and stimulated teams of proponents who are expected to develop competitive IODP proposals addressing oceanic geologic hazards. (Contact: Y. Kontar)
Updated 07/23/2012 SLD