SLIDE 1
Airborne Electromagnetics in the Marina Area
Marina Coast Water District
Ian Gottschalk and Rosemary Knight, Stanford University Aqua Geo Frameworks, Mitchell, NE
1
2 SkyTEM
Airborne Electromagnetics in the Marina Area Marina Coast Water - - PowerPoint PPT Presentation
Airborne Electromagnetics in the Marina Area Marina Coast Water - - PowerPoint PPT Presentation
Airborne Electromagnetics in the Marina Area Marina Coast Water District Ian Gottschalk and Rosemary Knight, Stanford University Aqua Geo Frameworks, Mitchell, NE 1 SkyTEM 2 Saltwater Intrusion cross section map view N Water Table
SLIDE 2
SLIDE 3
3
Freshwater Sealevel S e a f l
- r
Freshwater Saltwater Saltwater Water Table
N a a’ a a’ map view cross section
Tom Szenher
Saltwater Intrusion
SLIDE 4
4
?
How do we learn about what lies underneath?
SLIDE 5
5
?
How do we learn about what lies underneath?
SLIDE 6
6
?
How do we learn about what lies underneath?
SLIDE 7
7
?
How do we learn about what lies underneath? Complex scenarios can be difficult to decipher, even with many wells drilled
SLIDE 8
8
Geophysics as a method to learn about the subsurface
Goebel et al., 2017
SLIDE 9
9
Geophysics as a method to learn about the subsurface
Goebel et al., 2017
SLIDE 10
10
?
Airborne Electromagnetics
SLIDE 11
11
?
Airborne Electromagnetics
200-300m (650-1000ft) 30 m (100 ft) above the ground 80 km/hr (50 mph) 250-350 km (150-220 miles) flown in a day
SLIDE 12
12
SLIDE 13
13
Current flows around transmitter loop
SLIDE 14
14
Primary magnetic field generated Current flows around transmitter loop
SLIDE 15
15
Primary magnetic field generated Eddy currents induced in the ground depth depends on electrical conductivity Current flows around transmitter loop
SLIDE 16
16
Secondary magnetic field detected by receiver coils Primary magnetic field generated Eddy currents induced in the ground Current flows around transmitter loop
SLIDE 17
17
Resistivity profiles Elevation (m)
SLIDE 18
18
Resistivity profiles Elevation (m)
Saline Fresh
Saline Fresh
SLIDE 19
Resistivity measurements in wells
19
A B
Saline Fresh Salinas River Ocean Marina
SLIDE 20
Resistivity measurements in wells
20
Data recorded in 2015
A B
Saline Fresh Salinas River Ocean Marina
SLIDE 21
Resistivity measurements in wells
21
Saline Fresh
Saline Fresh
A B
Salinas River Ocean Marina
SLIDE 22
AEM data expands our knowledge
22
Saline Fresh
A B
Salinas River Ocean Marina
SLIDE 23
AEM data expands our knowledge
23
=Saline =Fresh
A B
Salinas River Ocean Marina
SLIDE 24
AEM data expands our knowledge
24
=Saline =Fresh
A B
Salinas River Ocean Marina
SLIDE 25
AEM data expands our knowledge
25
A B
Saline Fresh Salinas River Marina
SLIDE 26
AEM data expands our knowledge
26
Saline Fresh Salinas River Marina
A B
SLIDE 27
AEM data expands our knowledge
27
Saline Fresh Salinas River Marina
A B
SLIDE 28
AEM data expands our knowledge
28
=Saline =Fresh Saline Fresh Salinas River Marina
A B
SLIDE 29
AEM data expands our knowledge
29
Saline Fresh =Saline =Fresh Salinas River Marina
A B
SLIDE 30
The data in action (video clip)
30
SLIDE 31
Moving forward
31
geophysical properties that we measure
SLIDE 32
Moving forward
32
geophysical properties that we measure hydrogeologic information that we want
- water quality
- hydraulic conductivity
SLIDE 33
Thank You
33