Title: INTRODUCTION TO UTM COORDINATES AND MAP DATUMS
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3INTRODUCTION TO UTM COORDINATES AND MAP DATUMS
4UTM COORDINATES
300,000
700,000
500,000
105
108
102
105
ZONE CENTRAL MERIDIAN 500,000 m
5TRANSVERSE MERCATOR
6UTM ZONES UNITED STATES
NM
7UTM CARTISIAN COORDINATES
8USGS MAPS AND UTM
9COORDINATE SYSTEMS
- NAD 27 North American Datum, 1927
- NAV 29 North American Vertical, 1929
- NAD 83 North American Datum, 1983
- WGS 84 World Geodetic System 1984
- (ALL GPS)
- CORPSCON CONVERSION PROGRAM
10- INTRODUCTION TO MAGNETIC METHODS
- Earths Magnetic Field
- Rock Magnetism
- Geologic Models Magnetic Anomaly Sources
- Planning a Survey
- Examples
REFERENCE Sheldon Breiner, Applications Manual
for Portable Magnetometers www.georentals.co.uk/am
pm-opt.pdf
11TOTAL FIELD MEASUREMENTS
12EARTHS DIPOLE FIELD
13MAGNETIC ELEMENTS
North
F Total Field Intensity I Inclination D
Declination H Horizontal Component X North
Component Y East Component Z Vertical
Component
East
H F cos I Z F sin I H tan I X cos D Y
H sin D X² Y² H² X² Y² Z² F²
14TOTAL INTENSITY
50
25
50
70
X 1000 nTeslas
15GEOMAGNETIC INCLINATION
80N
60N
0
60S
80S
GEOMAGNETIC INCLINATION DEGREES OF ARC FROM
HORIZONTAL
16CHANGES IN DECLINATION AND INCLINATION AT LONDON
SINCE 1540SECULAR VARIATIONS
Declination
2008
Inclination
17SOLAR DIURNAL VARIATIONS
MID NORTHERN AND MID SOUTHERN LATITUDES
EQUATORIAL LATITUDES
50 nT
18MICRO PULSATIONS
10 minutes
10 nT
19TYPICAL MAGNETIC STORM
50 nT
1 day
20CORRECTING FOR TIME VARYING FIELDS
- F f(x,y,z,t)
- x Easting (Longitude)
- y Northing (Latitude)
- z Elevation (very small effect)
- t time
- FB Field at Base Station (time dependent)
- FR Field at Rover (space/time dependent)
- FC Time Correct Field at Rover FB FR
- GEOREF Geomagnetic Reference Correction
21AVERAGE MAGNETIC SUSCEPTIBILITIES
BASIC IGENOUS
Magnetic Susceptibility x 106 (c.g.s.)
ACID IGNEOUS
METAMORPHIC
SEDIMENTARY
22MEASURED SUSCEPTIBILITIES OF ROCK MATERIALS
23INDUCED VS REMANENT MAGNETIZATION
- Induced Magnetization
- Polarization in direction of Earths Field
- Remanent Magnetization
- Thermoremanent (Curie Temperature)
- Detrital (Depositional)
- Chemical
24GEOLOGICAL MODEL REPRESENTATIONS OF COMMON
MAGNETIC ANOMALY SOURCES
25Dipoles vs. Monopoles vs. Arrays of Poles
26ANOMALIES FOR GEOLOGICAL BODIES AT VARIOUS
ORIENTATIONS AND FIELD INCLINATIONS
? F F F ?F ?F
T N-S T E-W T N-S T E-W
1 2 3 4 5
27TOTAL INTENSITY INDUCED DIPOLE SIGNATURESAT
VARIOUS INCLINATIONS OF THE FIELD
Induced dipole Vertical Field (North or South
Poles)
Induced dipole (Inclination 60º)
Induced dipole Equatorial Field (Inclination 0º)
28REMANENT DIPOLE SIGNATURESMOMENT NOT PARALLEL TO
INDUCING FIELD
29EFFECT OF DEPTH ON ANOMALY WIDTH
The amplitude of the anomaly is maintained
constant By adjusting the size of the anomalous
body.
30DEPTH/AMPLITUDE BEHAVIOR OF DIPOLE ANOMALIES
Note Same Amplitude but Change in width
M
8M
M
31F
500
1 ton iron
100
nT
10
1
200
10
Ft
DISTANCE
32ANOMALIES OF COMMON OBJECTS
- OBJECT Ft/nT
Ft/nT - Automobile (1 ton) 30/40 100/1
- Ship (1000 ton) 100/300-700 1000/1
- Aircraft (light) 20/10-30
50/1 - Pipeline (12) 25/50-200 50/12-50
- Wellhead 50/200-500 500/2-5
- Fenceline 10/15
25/1-2 - Rifle 5/10-50
10/ 2-10 - Revolver 5/10-20
10/1-2
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34TYPICAL MAGNETIC ANOMALIES OF COMMON
ARCHAEOLOGICAL FEATURES
Shallow grave or pathway
Humus-rich site of habitation
Kiln-baked brick wall
Sandstone wall in more magnetic soil
Bricks in disarray
Fire pit with bricks In original position
Shallow tomb
Deeply buried tomb
35PLANNING A SURVEY
- SIZE OF TARGET
- AERIAL EXTENT OF SEARCH
- GROUND OR AIRBORNE
- RESOLUTION OF SURVEY
- FIELD METHODS
- PITFALLS
- EXAMPLES
36TYPICAL SEQUENCES OF TRAVERSES DURING SEARCH
PROCEDURES
Object location
Total magnetic field contours (not known during
search)
Secondary Traverse
Primary Traverse
Primary Traverse
Primary Traverse
Final Traverse
37Maximum slope 5 m
52195 nT
52490 nT
GN
TN
52280 nT
Contour Interval 5 nT
38F
500
SOLUTION FOR BILLS CRATER
1 ton iron
100
nT
10
1
200
10
Ft
DISTANCE
39ESTIMATION OF DEPTH TO TOP OF ANOMALOUS BODIES
USING MAXIMUM SLOPE
40MAGNETIC EFFECT OF LATERAL SUSCEPTIBILITY CHANGE
VS STRUCTURE
41HIGH RESOLUTION AIRBORNE MAGNETIC MAP OF THE SAGE
2008 FIELD AREA
SAGE 2008 ARCH SITE
SAGE 2005 MT PROFILE
SAGE 2005 SEISMIC PROFILE