Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.

Slides:



Advertisements
Similar presentations
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Advertisements

Magnetism and Electricity Chapter 13. Reminders 1 Lab this week due by Friday at 4:00 pm: B3-CLE: Coulomb’s Law of Electrostatics Weekly Reflections #11.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Magnetic Methods (IV) Environmental and Exploration Geophysics I
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Tom Wilson, Department of Geology and Geography Geol 454 Environmental and Exploration Geophysics I tom.h.wilson Department of.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Magnetic Field Physics 102 Professor Lee Carkner Lecture 17.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
White board your results. In particular:
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Geomagnetism: Lecture 1 This lecture is based largely on:
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Outline Magnetic dipole moment Magnetization Magnetic induction
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h. wilson Department of Geology.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Magnetism GEO-3010 University of Utah Fan-Chi Lin.
Geomagnetism: Lecture 1 This lecture is based largely on:
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Subsurface model development using terrain conductivity measurements Tom Wilson, Department of Geology and Geography The problems in the text provide insights.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Geology 5660/6660 Applied Geophysics 28 Mar 2014 © A.R. Lowry 2014 For Mon 31 Mar: Burger (§7.4–7.6) Last Time: Earth’s Main Magnetic Field Earth’s.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
General review & continuation of Chapter 2 computer lab efforts tom.h.wilson Department of Geology and Geography West Virginia.
Magnetic Earth Chapter 1 Section 3 Pages Objective: Understand the Earth’s magnetic field and Compare magnetic and geographic poles. Compass:
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Recall that the proton precession magnetometer makes measurements of the total field, not the vector components of the field. Recall also that the total.
Tom Wilson, Department of Geology and Geography tom.h.wilson tom. Department of Geology and Geography West Virginia University Morgantown,
Environmental and Exploration Geophysics II t.h. wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Chapter 19 Magnetism. Magnetism is one of the most important fields in physics in terms of applications. Magnetism is closely linked with electricity.
Geology 5660/6660 Applied Geophysics 1 Apr 2016 © A.R. Lowry 2016 For Mon 4 Apr: Burger (§ ) Last Time: Magnetics (Measurement, Anomalies)
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV.
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Geology 5660/6660 Applied Geophysics 30 Mar 2016
Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown,
Geol 319: Important Dates Friday, Sept 28th – class cancelled
Magnetic Methods (III)
Magnetic Methods (V) Environmental and Exploration Geophysics I
Magnetic Methods- continued
Final review sessions - II
Tie up Gravity methods & begin Magnetic methods
Geology Geomath Estimating the coefficients of linear, exponential, polynomial, logarithmic, and power law expressions tom.h.wilson
Magnetic Methods (II) Environmental and Exploration Geophysics I
Geology Geomath Estimating the coefficients of linear, exponential, polynomial, logarithmic, and power law expressions tom.h.wilson
Final Review – session 2 Environmental and Exploration Geophysics I
Presentation transcript:

Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics I tom.h.wilson Department of Geology and Geography West Virginia University Morgantown, WV Intro to magnetic methods

Tom Wilson, Department of Geology and Geography The Earth’s magnetic field

Magnetic polarity reversals occur on average about 4 to 5 times per million years Tom Wilson, Department of Geology and Geography

Location of north magnetic pole Tom Wilson, Department of Geology and Geography

The Earth’s magnetic field is also very dynamic on short time scales Tom Wilson, Department of Geology and Geography Charged particles from the sun stream into the earth’s magnetic field and crash into the gasses of the upper atmosphere

Tom Wilson, Department of Geology and Geography Protons and electrons in the solar wind crash into earth’s magnetosphere.

Comet ISON has two tails! Tom Wilson, Department of Geology and Geography

Field surveys Tom Wilson, Department of Geology and Geography

Making measurements of the Earth’s magnetic field Tom Wilson, Department of Geology and Geography Steve Sheriff’s Environmental Geophysics CourseEnvironmental Geophysics Proton Precession Magnetometers Tom Boyd’s Introduction to Geophysical Exploration CourseIntroduction to Geophysical Exploration Water, kerosene & alcohol

Tom Wilson, Department of Geology and Geography Source of Protons and DC current source Proton precession generates an alternating current in the surrounding coil Magnetic Fields – Basic Relationships

Tom Wilson, Department of Geology and Geography Proton precession frequency (f) is directly proportional to the main magnetic field intensity F and magnetic dipole moment of the proton (M). L is the angular momentum of the proton and G is the gyromagnetic ratio which is a constant for all protons (G = M/L =  -sec). Hence -

Locate trench boundaries and map distributions of metallic debris Tom Wilson, Department of Geology and Geography Theoretical model Examination of trench for internal magnetic anomalies. actual field data. Gilkeson et al., 1986

Abandoned wells Tom Wilson, Department of Geology and Geography From Martinek

Tom Wilson, Department of Geology and Geography Gochioco and Ruev, 2006 We are also interested in local induced magnetic fields produced by metallic objects Where are the abandoned wells?

Anomalous fields from abandoned wells often produce large distinctive anomalies Tom Wilson, Department of Geology and Geography Locating abandoned wells

Raised relief display Tom Wilson, Department of Geology and Geography From Martinek raised relief plot of measured magnetic field intensities

Measurement of different field components: total, vertical and horizontal gradients Tom Wilson, Department of Geology and Geography

Test site Tom Wilson, Department of Geology and Geography

Results of field tests Tom Wilson, Department of Geology and Geography

Magnetic monopoles p1p1 p2p2 r 12 F m12 Magnetic Force  Magnetic Permeability p 1 and p 2 pole strengths Coulomb’s Law Magnetic Fields – Basic Relationships

Tom Wilson, Department of Geology and Geography Force Magnetic Field Intensity often written as H p t is an isolated test pole The text uses F instead of H to represent magnetic field intensity, especially when referring to that of the Earth (F E ). Magnetic Fields – Basic Relationships

Magnetic fields – basic relationships Tom Wilson, Department of Geology and Geography The fundamental magnetic element is a dipole or combination of one positive and one negative magnetic monopole. The characteristics of the magnetic field are derived from the combined effects of non-existent monopoles. Dipole Field

Tom Wilson, Department of Geology and Geography monopole vs. dipole Toxic Waste Magnetic fields – basic relationships

The Earth’s main magnetic field Tom Wilson, Department of Geology and Geography

Magnetic “Elements” Tom Wilson, Department of Geology and Geography

Magnetic “Elements”

Tom Wilson, Department of Geology and Geography Magnetic “Elements”

Tom Wilson, Department of Geology and Geography Magnetic “Elements”

Tom Wilson, Department of Geology and Geography Magnetic north pole: point where field lines point vertically downward Geomagnetic north pole: pole associated with the dipole approximation of the earth’s magnetic field. The compass needle points to the magnetic north pole.

Magnetic field intensity in Morgantown, WV Tom Wilson, Department of Geology and Geography The drop is associated with the westerly rotation of the earth’s magnetic field.

Magnetic Inclination Tom Wilson, Department of Geology and Geography

Magnetic inclination in the Morgantown area Tom Wilson, Department of Geology and Geography westerly rotation of the earth’s magnetic field produces the current decrease in inclination

Magnetic declination Currently the compass point west of true north Tom Wilson, Department of Geology and Geography

Magnetic declination and its variation through time Tom Wilson, Department of Geology and Geography West declination is negative

Tom Wilson, Department of Geology and Geography Magnetic Elements for your location

Magnetic elements Tom Wilson, Department of Geology and Geography

Tom Wilson, Department of Geology and Geography Anomaly associated with buried metallic materials Bedrock configuration determined from gravity survey Results obtained from inverse modeling Computed magnetic field produced by bedrock Introduction to the magnetics computer lab

Let’s get started Tom Wilson, Department of Geology and Geography Where are the drums and how many are there?

Tom Wilson, Department of Geology and Geography Items on the list …. Gravity paper summary(s) (both sections) due today, Nov. 14th Gravity lab will be due on Thursday November 21 st (writing section submission is self-reviewed showing track changes). Gravity lab – last chance for questions this coming Tuesday Keep reading Chapter 7. We will have two final exam review sessions: December 5 th and December 10 th. Final is from 3-5pm on December 13 th.

Regular section submissions Tom Wilson, Department of Geology and Geography All those in the regular section submit paper copies of your paper summaries and lab reports.

Writing Section reminders (electronic submissions only) Tom Wilson, Department of Geology and Geography Revised paper summary 1 and self-reviewed paper summary 2 are due today. The gravity lab is self reviewed and is due on Thursday, November 21 st. All those in the writing section submit their papers and lab electronically. Don’t forget to turn on track changes while doing your self- review. Only submit the self-reviewed file.

What’s coming up? Some due date reminders Tom Wilson, Department of Geology and Geography