Emily Maher, Brian Kuhns, and Slava Russky Magnetics Emily Maher, Brian Kuhns, and Slava Russky

What is Magnetics? A magnetic survey is used to record spatial variations in the Earth’s magnetic field. Our team took the time to create a manual for future students to use when downloading magnetics field data because there was not a reliable source available.

Device Information A Gemlink GSM-19 was used to collect the magnetic changes across a set path or “line” The device has a mobile unit and a base station. The base station is used to record any changes in the regular magnetic field, while the mobile unit is moved along a line in order to find changes in ground composition. The data from the base station for line 1 was not transferred fully, so there is no data that can be compared for that day. Since there were no magnetic anomalies on March 20th & 21st, the base station measurements from day 2 can be used for day 1.

Checking the Space Weather Forecast Information Provided by Natural Resources Canada http://www.spaceweather.gc.ca/index-en.php Space Weather: Physical process that begin with the sun and affect human activity on earth and in space. What causes a geomagnetic storm? Explosive activity on the sun releases charged particles that travel to earth. Causes disturbances in magnitude and direction of earth’s magnetic field “they can directly affect operations that rely on the Earth's magnetic field, such as magnetic surveys done by mineral exploration companies” Days of Concern: Day 1 - March 20th 2016 Day 2 - March 21st 2016 *Used Victoria – VIC station since it is the closest to the study area

Space Weather – Day 1 *Variations are very low and no filtering needs to be made to field data.

Space Weather – Day 2 *Variations are very low and no filtering needs to be made to field data.

Location of Lines There were two lines of magnetic measurements taken. Both of these were done at the 7 Lakes location, North of Reno

Line 1 This line ran along 395 The entire line was along a barbwire fence, and over a bridge. All of these things could affect the data that was collected.

Line 2 This line actually ran over the anticline. On the day that this data was collected there was a very strong wind. This might have affected the collection of the data making it less valid.

Results : Line 1 There is a gap in the data because area in which all the school vehicles were parked was skipped.

Base Station There is a small amount of change in the base station measurements (~30nT). The measurements were taken between 9:07am and 2:07pm on March 21st, 2016.

Results: Line 2 Mobile Unit The variation in base station measurements (+- 30nT) relative to the variation in the mobile unit (+-1200 nT) is minimal. The mobile measurements do not need to be filtered based on the base station measurements.

Magnetic Range There was a difference of magnetic measurements of the base station was simply 30 nanoTeslas. This is a small change in the scheme of things. There was a variance of the following for the mobile station readings: Line 1: 404.9 nT Line 2: 1220.52 nT

Analysis We will used the chart in the book to attempt to analyze the data. There were no excess calculations done to determine actual values, so this is a rough estimate.

USGS California and Nevada Geologic Maps Available in google drive – Magnetic Data 7 Lakes Line 1 Line 2

Line 1

Line 1: Cont.

Line 2 128 109

Line 2 55 68 Both spots indicated on USGS map of honey lake fault zone appear to be confirmed by plotted results geometry

Line 2 186 *Potentially where the fault crossing the reflection/refraction line intersects magnetics line 2

Peaks & Lows Line 1: Line 2: 49956.82nT – 39.9494947° -120.0304199°

Uncertainty and Room For Improvement Biggest Problems occurred on Day 2 Magnetics readings taken incorrectly Coordinates taken incorrectly Distances not recorded between points How to fix Accuracy and precision require repeatability in methods Allow magnetics team member to remain with line at times Line 2 Points

References Telford, W. M., L. P. Geldart, and Robert E. Sheriff. Applied Geophysics. Cambridge: Cambridge UP, 1990. Print.