Airborne Geophysics to Map Groundwater Bill Brown bb@skytem.com
A 6 borehole represents 1 millionth of an acre
Aquifer Materials An aquifer is an underground layer of water bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt) from which groundwater can be extracted Arizona Well Owner's Guide to Water Supply Janick F. Kristine Artiola Kristine Uhlman
Airborne Electromagnetics Faraday s law of induction Records subsurface resistivities/conductivities Depth range 0-500 metres
Resistivity/Conductivity values
Resistivity link to Hydrogeology Resistivity vs. K High Low Conceptual hydrological model Very low
Time-domain EM Digital video camera TEM receiver coils Generator Pitch & roll sensor Laser altimeter Transmitter coil suncor GPS Inclinometers Laser altimeter Transmitter Magnetometer
Nebraska Natural Resources Department 15 Miles X 12 miles
Nebraska Natural Resources Department ~ 500 sq mi
Resistivity versus Lithology and Aquifer Materials Non Aquifer Marginal Aquifer Principal Aquifer Coarse Aquifer 39 boreholes with lithology and resistivity geophysical logs ~209,000 individual measurements
50 m bgl 12 kms X 7 kms Data courtesy of NE Lower Platte South NRD and XRI Geophysics
150 m bgl 12 kms X 7 kms Data courtesy of NE Lower Platte South NRD and XRI Geophysics
250 m bgl 12 kms X 7 kms Data courtesy of NE Lower Platte South NRD and XRI Geophysics
Thickness 305 Depth to Top 126 Top Elevation 1392 Depth to Bottom 431 Bottom Elevation 1087 Thickness 38 Depth to Top 68 Top Elevation 1236 Depth to Bottom 106 Bottom Elevation 1198
Horn River Basin, B.C. 2011 Is airborne geophysics applicable to mapping groundwater in the area? Participants 1-Stone Mountain Resources 2-Quicksilver Resources 3-EOG Resources 4-Imperial Oil/Exxon Data courtesy of Geoscience BC
Horn River Basin - Imperial Oil/Exxon 10 mi X 5 mi Top 6 feet Data courtesy of Geoscience BC
45 ft depth 10 mi X 5 mi Data courtesy of Geoscience BC
90 ft depth 10 mi X 5 mi Data courtesy of Geoscience BC
10 miles X 5 miles 300 foot depth Data courtesy of Geoscience BC
10 mi X 5 mi 450 ft depth Data courtesy of Geoscience BC
Near Surface Mapping Location of Construction Materials and potential recharge areas- top 10-15 ft Resistivity 2m depth d-66-f Data courtesy of EOG Resources Ohm m
Ft. Irwin National Training Center Northern Mojave Desert, California Ft. Irwin China Lake Naval Weapons Reserve Nelson Basin Fort Irwin National Training Center AEM flight line 2011 and 2014 survey: https://pubs.usgs.gov/of/2013/1024/
Fort Irwin, Nelson Basin Qap - salt plia Tba - basaltic flows Td - volcanics in middle of basin Fpg granitic rock up against deformed clay? data courtesy of the USGS
Fort Irwin, Nelson Basin Td volcanics Fpg granitic rock Tv sediments, clays data courtesy of the USGS
Development of 3D groundwater model domain resistivity Borehole hydrostratigraphy Quat. alluvium Fine-grained units Surface geology Generalized rock unit Playa/gw deposit Basin-fill deposit Volcanic-rich/ Tuffaceous units Volcanic dome/flow Partially consolidated rock Plutonic rock 5 km Conglomerate and sandstone AEM inverted resistivity South North Groundwater Model domain Dacite Dome 7 parameter zones within the Nelson basin were developed using resistivity distributions of known geologic units Granitic basement (interpreted from AEM and gravity models and masked as no-flow boundary) (Ball et al, in prep) PRELIMINARY; SUBJECT TO REVISION
Subsurface mapping with airborne electromagnetics in the Central Valley of California Rosemary Knight and Ryan Smith, Stanford University; Ted Asch, Jared Abraham, and James Cannia, Aqua Geo Frameworks; Andrea Viezzoli, Aarhus Geophysics ApS
SALINITY MAPPING, MURRAY RIVER, AUSTRALIA 3 mi X 7 mi
Salt Water Encroachment http://www.nature.com/articles/ncomms7831
Airborne electromagnetic surveys provide high-quality subsurface data for building complex hydrogeologic frameworks Airborne electromagnetic surveys: A quantitative tool for groundwater management J. Abraham, J.Cannia, B.Mimsley USGS GEM Beijing 2011
The root of the word rival is from the Latin world rivalis which means a person using the same river Mississippi and Tennessee Representatives Discuss Water Allocation Without Their Lawyers www.aquadoc.com
Acknowledgments Lower Platte South NRD
Mapping Targets Fresh/saline/contaminated water Clay layers Faulting Overburden thickness Produced waters Depth to/thickness and breadth of aquifers Glacial aquifers and thickness of permafrost Alteration/Landslides on volcanoes Geothermal Karst Mineral Deposits
Inaccessible or rough terrain
Why airborne geophysics? Airborne resistivity ~ 70 95 mph Ground-based resistivity ~ 1 mile /day Lake talik permafrost Abraham, 2012 Minsley et. al., 2012
Denmark s Aquifers Identify areas valuable for drinking water Data used to establish sitespecific groundwater protection zones and regulation of land use to prevent groundwater pollution Public pays $0.08 per m³ surcharge for the mapping or about $12 year