USGS - U.S. Geological Survey
08/26/2021 | Press release | Distributed by Public on 08/26/2021 16:59
Media Alert: Flights Above the Mississippi Alluvial Plain and Adjacent Areas to Continue Aquifer Mapping
A low-flying airplane will soon be visible to residents in the multi-state area comprising the Mississippi Alluvial Plain (MAP), as well as adjacent areas in the Mississippi Embayment and Chicot Aquifer, marking the beginning of the next stage of a high-resolution airborne survey project to map aquifers.
Coordinated by USGS scientists to map the properties of aquifers throughout parts of the MAP, the low-level flights are intended to provide critical data needed by state and local decisionmakers to evaluate and manage groundwater resources in the region. The MAP is one of the most productive agricultural regions in the nation and depends on groundwater for irrigation. It constitutes the third-largest area of irrigated cropland in the U.S., consisting of approximately 29,000 square miles, or 19 million acres, and includes parts of Missouri, Tennessee, Arkansas, Mississippi, Louisiana, Kentucky and Illinois.
Beginning in late August and lasting for 2-3 months, an airplane contracted by the USGS and operated by Xcalibur Multiphysics of Ontario, Canada, will make low-level flights over more than 20 million acres and seven states within the MAP and adjacent areas. Experienced pilots specially trained and approved for low-level flying will operate the aircraft. All flights are coordinated with the FAA to ensure accordance with U.S. law. The flights will initially be based out of Greenwood-Leflore Airport in Mississippi, then will work from other airports in the region as the survey progresses. Follow the planned flight lines here.
Previous phases of airborne geophysical data acquisition over the MAP region using the same airplane and instrumentation occurred in late 2019 to early 2020, as well as multiple helicopter surveys over the region from 2018 to 2021. Examples of the products generated from the previous surveys include the recently published interactive maps of the high-resolution survey near Shellmound, Mississippi, and of the regional, MAP-wide surveys.
Instruments on the airplane will collect information about the geology in shallow aquifers of the region. When the data analysis is complete, resulting state-of-the-art maps will help USGS researchers understand the aquifer system that supports groundwater resources at depths up to about 1,000 feet underground.
This survey will be flown mainly east-west at an altitude of 400 feet along lines spaced approximately four miles apart. The airplane will have an attached electromagnetic instrument housed in a small receiver that is towed 300 feet behind and about 150 feet beneath the aircraft. All survey flights will occur during daylight hours.
Residents and visitors should not be alarmed to witness a low-flying aircraft with a small sensor towed behind it. The airplane will also carry scientific instruments including a magnetometer and a gamma-ray spectrometer. None of the instruments pose a health risk to people or animals, and flights will not occur directly above populated areas.
The survey is being conducted by the USGS Water Availability and Use Program as part of the MAP Regional Water Availability Study. More information about the MAP project can be found online.
Map of Mississippi Alluvial Plain flight line plan. Planned flight lines in blue, previously completed lines in brown. Access the most updated version here.
(Public domain.)
Airplane that will conduct low-level flights. Beneath the plane is a 'bird' receiver (shown here in its stowed position under the aircraft) which will be towed behind the aircraft during the survey. Operated by Xcalibur Multiphysics under contract to the USGS. Photo courtesy Xcalibur Multiphysics.
(Public domain.)