Z-Axis Tipper Electromagnetic Ground Surveys

AlexJ · January 14, 2020, 7:05pm

Aurora Geosciences (AGL) based out of Whitehorse would like some assistance on inverting a public domain data set of Extremely Low Frequency (ELF) and gravity surveys .
The ELF surveys were conducted by an AGL ground geophysical crew. The data collected is Z-Axis Tipper Electromagnetics. We are not referencing an E- Field. We are just reading the inphase and quadrature tilt angle of the magnetic field at frequencies from 11Hz to 1440Hz.
There is no controlled source involved, and there are no electric dipoles being measured. It is a passive system.There is no base station in use either.
We can provide all technical specs, the data is similar to ZTEM tipper data

I have attached a written confirmation that the data set from the Yukon Geological Survey has released the data set to AGL and placed into the public domain.

.

AlexJ · January 14, 2020, 7:09pm

A Gravity survey , conducted for the Yukon Geological Survey (YGS), was used to assist in the imaging of the Denali fault for Geothermal exploration.The survey was conducted in a 10 km X 7 km area located within NTS map sheet 115 G/4 with a station separation of 250 m and a line separation of 1000 m.In total 295 data points were collected in the 2019 program between March 15, 2019 and April 3, 2019.

An ELF survey consisting of 329 data points was conducted from June 12th to June 29th, 2019.
The survey consisted of eleven 7000 m lines with stations every 250 m. The in-phase & quadrature maps for the N/E component profile lines, tipper vectors, & divergence plots for all measured frequencies (11, 22, 45, 90, 180, 360, 720, & 1440 Hz) were plotted and modeled.

Logistical and technical Geophysical reports for the above surveys have been written by AGL and submitted to YGS during 2019.

I have attached a poster "Geothermal Studies by the Yukon Geological Survey " as a pdf. This poster was presented at the 2019 Yukon Geoscience Forum.
Geothermal YGF 2019_lores.pdf (3.8 MB)

AlexJ · January 14, 2020, 7:15pm

I have attached the crew logs, the logistical report and the technical report here.YGS-20190723-Burwash_ELF_Survey_Techinical_Report.pdf (228.6 KB) YGS-20190702-Burwash_ELF_Survey_Field_Report.pdf (847.5 KB) YGS-20190629-YGS ELF crew log.pdf (100.3 KB)

AlexJ · January 14, 2020, 7:32pm

I have attached the PDF files of the Final Products from the report submitted to YGS in 2019

AlexJ · January 14, 2020, 9:27pm

I have included the raw data from Line 5000 at the bottom of this post, and I have attached a pdf the contains a description of the columns

YGS-20191209 Description of the colums in the ELF observations.pdf (181.0 KB) Raw Data contains a CSV file of the observations and a pdf containing a description of the columns of the CSV.
Since I currently only have permissions to attache image files and pdfs, I attempted to attach a pdf of the raw data. The PDF was not able to preserve some formatting when i copied the contents back into csv.
For this reason, I have attached the raw data here. I was able to copy and paste the text below into a MS spreadsheet by using a white space deliminator. So I hope that you will be able to do the same.

Line Station Lat Long E_WGS84_Z7 N_WGS84_Z7 ALT Az Dur Noise rE_0011 rE_0022 rE_0045 rE_0090 rE_0180 rE_0360 rE_0720 rE_1440 rN_0011 rN_0022 rN_0045 rN_0090 rN_0180 rN_0360 rN_0720 rN_1440 iE_0011 iE_0022 iE_0045 iE_0090 iE_0180 iE_0360 iE_0720 iE_1440 iN_0011 iN_0022 iN_0045 iN_0090 iN_0180 iN_0360 iN_0720 iN_1440 SNI_0011 SNI_0022 SNI_0045 SNI_0090 SNI_0180 SNI_0360 SNI_0720 SNI_1440
5000 0 61.33295316 -139.1931461 596692 6801212 1015 294.3 144 0 -0.107 -0.042 -0.033 0.002 0.037 0.06 0.071 0.01 -0.239 -0.154 -0.161 -0.157 -0.133 -0.088 -0.041 -0.018 0.012 0.045 0.057 0.065 0.05 -0.011 -0.051 -0.099 -0.022 -0.027 0.001 0.03 0.06 0.072 0.062 0.023 38.6 160.2 385.1 603.8 484.1 455.3 704.7 477.2
5000 0 61.33295316 -139.1931461 596692 6801212 1015 216.2 183 0 0.328 0.024 -0.019 -0.022 0.018 0.07 0.079 0.022 -0.314 -0.168 -0.164 -0.151 -0.14 -0.107 -0.066 -0.037 -0.045 0.002 0.027 0.071 0.063 0.02 -0.043 -0.103 -0.055 -0.01 -0.005 0.01 0.041 0.067 0.071 0.041 63.3 204.5 504.1 845.6 724.8 448.7 581 366.5
5000 250 61.33458935 -139.1899118 596860 6801399 977.8 151.3 188 0 -0.009 -0.046 -0.047 -0.024 0.018 0.105 0.245 0.399 -0.138 -0.167 -0.191 -0.218 -0.225 -0.198 -0.143 0.095 0.047 0.028 0.045 0.063 0.074 0.043 -0.03 -0.149 -0.087 -0.068 -0.055 -0.026 0.008 0.044 0.042 -0.007 67.6 207.4 491.3 742.5 544.4 155.9 165.1 145.6
5000 500 61.33623517 -139.1867326 597025 6801587 1002.1 40.4 147 0 -0.256 -0.053 -0.042 0 0.038 0.093 0.117 0.111 -0.118 -0.178 -0.212 -0.245 -0.252 -0.226 -0.171 -0.094 0.124 0.059 0.053 0.062 0.063 0.049 0.029 -0.032 -0.091 -0.068 -0.054 -0.023 0.021 0.081 0.125 0.139 41 150.2 324.8 585.7 542.6 482.1 418 128
5000 750 61.33802624 -139.1836755 597183 6801791 990.7 40.7 263 0 -0.446 -0.038 -0.018 0.003 0.031 0.093 0.299 0.653 -0.048 -0.134 -0.152 -0.172 -0.176 -0.171 -0.121 0.045 0.028 0.055 0.045 0.061 0.077 0.083 0.02 -0.195 -0.039 -0.036 -0.033 -0.018 0.001 0.019 0.032 0.035 50.5 206.8 510.2 736.4 538.5 342.3 178.1 16.6
5000 1000 61.33945685 -139.1811998 597311 6801954 966.2 265.1 273 0 0.179 -0.017 -0.017 -0.016 -0.017 -0.014 -0.132 -0.246 -0.065 -0.025 -0.007 0.007 0.028 0.042 0.023 -0.019 0.091 0.019 0.024 0.031 0.046 0.068 0.094 0.08 -0.008 0.03 0.03 0.03 0.03 0.017 0.005 -0.001 34.6 179.6 521.7 830.8 708.4 253.2 147.5 45.8
5000 1000 61.33945685 -139.1811998 597311 6801954 966.2 346.6 223 0 -0.997 -0.05 -0.03 -0.032 -0.029 -0.034 0.083 -0.007 0.008 0.02 0.038 0.047 -0.059 0.019 0.019 0.028 0.046 0.075 0.053 -0.064 -0.044 0.027 0.033 0.032 0.033 0.025 0.016 -0.043 32 145.1 364.2 567.5 547.2 663.9 462.4 54.8
5000 1250 61.34134619 -139.1774446 597506 6802170 948 105.4 299 0 -0.901 0.003 0.017 0.027 0.032 -0.239 0.219 0.062 0.062 0.049 0.024 -0.018 0.193 0.038 0.026 0.025 0.02 0.082 0.086 0.124 -0.007 0.023 0 -0.034 -0.051 -0.052 -0.006 -0.072 24.7 157.1 495.5 763.9 573 41 183.6 98.5
5000 1500 61.34292716 -139.174137 597678 6802351 909.5 194.6 274 0.2 0.702 0.08 0.114 0.128 0.133 0.145 0.468 0.614 -0.086 0.109 0.121 0.109 0.07 0.019 -0.086 -0.08 -0.233 0.038 0.038 0.004 -0.026 -0.061 -0.096 0.035 0.233 0.049 0.005 -0.041 -0.066 -0.067 -0.056 -0.077 31.1 190.8 615.9 1029.6 828.2 194.7 48.5 9.2
5000 1750 61.3446646 -139.1711191 597834 6802549 902.2 188.5 240 0 0.088 0.159 0.184 0.212 0.226 0.138 0.164 0.188 0.233 0.252 0.242 0.234 0.14 0.1 0.074 0.049 0.016 0.007 -0.032 0.11 0.113 0.1 0.067 0.022 -0.002 -0.019 0.03 -0.02 34.7 157.8 380.8 742.9 605.7 60.7 25.6 17.8
5000 2000 61.34618612 -139.168076 597992 6802723 891.1 285.6 215 0 0.138 0.074 0.091 0.106 0.107 0.113 -0.009 -0.2 -0.019 0.165 0.207 0.211 0.182 0.143 0.083 0.272 0.244 0.069 0.039 0.01 -0.025 -0.034 -0.231 0.111 0.088 0.045 -0.017 -0.056 -0.08 -0.134 12.8 139.5 376.9 592 387.6 83 25.6 0
5000 2000 61.34618612 -139.168076 597992 6802723 891.1 1.4 212 0 0.036 0.04 0.048 0.059 0.06 0.043 0.409 0.191 0.239 0.244 0.209 0.164 0.115 0.319 0.142 0.052 0.027 0.009 -0.009 -0.018 -0.044 -0.041 0.155 0.098 0.051 -0.024 -0.071 -0.097 -0.108 -0.077 27.7 141.9 384.9 621.1 468.9 528.9 436.1 31.6
5000 2250 61.34794011 -139.1649629 598153 6802923 916.7 236.7 258 0 0.077 0.089 0.078 0.037 -0.032 -0.048 0.144 0.158 0.149 0.11 0.07 0.011 0.049 0.011 -0.043 -0.063 -0.083 -0.177 0.08 0.021 -0.034 -0.068 -0.065 0.013 24.8 112.3 413.1 684.7 469.5 292.3 221.9 76.2
5000 2500 61.34967013 -139.1620753 598302 6803120 935.2 130.2 123 0 0.039 0.041 0.026 -0.016 -0.067 -0.14 -0.203 -0.13 0.146 0.119 0.13 0.11 0.058 0.001 -0.04 -0.107 0.031 0.005 -0.034 -0.078 -0.112 -0.131 -0.142 -0.034 0.026 0.049 0.002 -0.056 -0.086 -0.087 -0.066 -0.053 42.5 147.8 363 486.8 418 418.4 218.8 20.1
5000 2750 61.35133223 -139.1588173 598471 6803310 989.7 336.6 180 0 -0.081 -0.041 -0.025 -0.04 -0.061 -0.078 -0.099 -0.122 -0.006 0.056 0.071 0.043 -0.003 -0.046 -0.081 -0.088 0.092 0.022 0 -0.023 -0.027 -0.021 -0.01 -0.005 0.099 0.044 -0.006 -0.052 -0.067 -0.056 -0.027 0.008 33 145 406.5 771.5 1317.7 1987.1 1204.5 178.7
5000 3000 61.35316032 -139.1558859 598622 6803518 982.9 267.7 180 0 -0.018 -0.005 0.003 -0.012 -0.02 -0.029 -0.042 -0.062 -0.053 0.015 0.024 0.01 -0.012 -0.029 -0.024 -0.023 0.101 0.042 0.014 -0.008 -0.009 0.004 0.048 0.07 0.036 0.008 -0.026 -0.027 -0.021 -0.025 39.2 171.1 425 684 518.7 277.4 167 52.6
5000 3000 61.35316032 -139.1558859 598622 6803518 982.9 179.6 177 0 0.012 0.015 0.009 0 -0.016 -0.046 -0.07 -0.173 0.013 0.026 0.043 0.025 0.004 -0.008 0.001 0.08 0.124 0.055 0.009 -0.012 -0.016 -0.011 0 0.198 -0.012 0.041 0.001 -0.022 -0.028 -0.014 -0.009 -0.106 36.6 140.1 402.9 657.3 453 175.1 178.8 17.5
5000 3250 61.35469588 -139.1525786 598794 6803694 975.4 89.2 309 0 -0.166 -0.012 0.012 0.022 0.055 0.078 0.009 0.03 0.033 0.041 0.062 0.086 0.091 0.036 0.033 0.031 0.027 0.035 0.069 0.054 0.036 0.028 0.036 0.04 0.026 0.032 29.3 75.2 360 721 547.2 457.2 242.9 43.9
5000 3500 61.35643206 -139.1495022 598953 6803892 955.9 282.2 180 0 0.204 0.01 0.022 0.054 0.076 0.14 0.232 -0.217 -0.07 -0.048 -0.049 -0.031 -0.007 -0.011 0.031 0.075 0.067 0.074 0.077 0.068 0.024 0.025 0.032 0.028 0.03 0.041 0.048 0.054 27.4 129.4 345.9 529.9 382.1 206.2 125.8 13.5
5000 3750 61.35801488 -139.1463785 599115 6804073 958 68.3 215 0 -0.08 -0.014 0.028 0.058 0.088 0.144 -0.043 -0.062 -0.063 -0.048 -0.016 0.028 0.114 0.075 0.066 0.058 0.061 0.071 0.026 0.049 0.034 0.029 0.038 0.052 0.062 0.143 26.6 121 309.2 517.4 333.6 109 47.1 0
5000 4000 61.3598227 -139.1432972 599274 6804279 934.2 160.9 179 5.3 -0.076 -0.062 -0.038 -0.024 -0.02 -0.025 -0.031 -0.111 -0.119 -0.117 -0.116 -0.106 -0.079 -0.093 0.106 0.039 0.037 0.028 0.023 0.02 0.024 0 0.004 0.003 0.017 0.029 0.043 0.063 39.3 165.6 412.6 660 434.2 117.1 98.8 0
5000 4000 61.3598227 -139.1432972 599274 6804279 934.2 45.2 134 0 -0.168 -0.042 -0.026 -0.011 -0.004 0.006 0.001 0.173 -0.202 -0.124 -0.117 -0.117 -0.106 -0.085 -0.09 -0.163 0.02 0.049 0.039 0.029 0.02 0.024 0.011 0.097 0.034 0.018 0.027 0.037 0.043 0.067 29.8 154.7 376 579.6 331 99.1 75.6 0
5000 4250 61.36154099 -139.1402396 599432 6804475 913.3 228.1 241 0 0.11 -0.072 -0.085 -0.077 -0.084 -0.146 -0.413 -0.167 -0.156 -0.165 -0.162 -0.163 -0.021 0.035 0.015 -0.004 -0.019 -0.032 -0.027 -0.01 -0.013 -0.011 -0.002 0.007 0.016 0.036 40.3 190.4 527.7 789.6 522.9 123.1 271.8 14.5
5000 4500 61.36312435 -139.137171 599591 6804656 898.3 211.4 128 0 0.012 -0.067 -0.041 -0.016 -0.006 0.021 0.041 -0.181 -0.112 -0.093 -0.057 -0.017 0.022 0.075 0.076 0.068 0.06 0.046 0.032 0.048 0.049 -0.012 0.043 0.057 0.073 0.085 0.086 0.082 29.9 154.7 339.9 505.1 319.4 241.6 221.3 0
5000 4750 61.36483172 -139.1339824 599756 6804851 880.6 191.6 159 0 0.032 -0.046 -0.006 0.03 0.052 0.073 0.081 -0.113 -0.075 -0.05 0 0.041 0.071 0.07 0.125 0.095 0.077 0.065 0.053 0.031 0.008 -0.004 0.054 0.076 0.074 0.064 0.039 0.001 37.4 169.9 388.2 596.7 453.6 312.3 140.1 0.6
5000 5000 61.36649544 -139.1308896 599916 6805041 855 218.7 121 0 -0.055 -0.041 0.005 0.058 0.087 0.098 0.1 0.09 -0.106 -0.061 -0.017 0.048 0.084 0.11 0.105 0.106 0.087 0.1 0.099 0.075 0.048 0.022 -0.001 -0.016 0.019 0.065 0.079 0.075 0.055 0.027 0.006 0.01 166.7 307.3 476.8 631.7 1005.5 1857.5 4405.7 5544
5000 5000 61.36649544 -139.1308896 599916 6805041 855 287.5 67 0 -0.012 -0.035 0.023 0.043 0.057 0.069 0.07 0.055 -0.139 -0.072 -0.014 0.047 0.093 0.116 0.123 0.126 0.098 0.084 0.066 0.042 0.033 0.013 -0.007 -0.015 0.043 0.086 0.101 0.096 0.069 0.043 0.023 0.011 111.3 208.6 295.3 441.3 742.7 1191.7 2819.7 4503.6
5000 5250 61.36816012 -139.1278713 600072 6805231 850.9 115.5 201 0.1 -0.005 0.043 0.056 0.055 0.05 0.038 0.066 0.059 0.076 0.074 0.058 0.045 0.033 0.127 0.06 0.039 0.015 -0.002 -0.015 -0.025 0.036 0.039 0.072 0.054 0.023 -0.005 -0.021 -0.03 66.2 135.3 279.7 998.1 1448.1 2239 2381.2 3495.5
5000 5500 61.36967012 -139.1247122 600236 6805404 849.9 242.4 128 0.3 0 0.026 0.041 0.043 0.042 0.006 -0.024 -0.054 -0.019 0.019 0.029 0.021 0.003 -0.012 0.034 0.043 0.046 0.026 0.006 -0.003 -0.012 -0.032 0.036 0.048 0.052 0.036 0.013 -0.003 -0.007 -0.012 32.3 134.5 298.1 589.7 682.2 467.2 216.5 315.9
5000 5750 61.37149332 -139.1214778 600403 6805612 844.8 244.8 163 0 0.023 -0.049 -0.009 0.008 0.027 0.025 0.023 0.023 -0.064 -0.014 -0.012 0.008 0.008 0.01 0.016 0.012 -0.013 0.041 0.013 0.009 0.004 0.007 -0.002 0.072 0.034 0.032 0.011 0.001 -0.005 0.013 20.6 140.4 387.4 541.2 837.5 1175.4 2005.4 3583
5000 6000 61.3731847 -139.1184569 600559 6805805 843.5 320.3 121 14.9 -0.036 -0.021 -0.008 0.004 0.004 0.019 0.026 0.002 -0.073 -0.049 -0.033 -0.011 0 0.008 0.022 0.002 -0.027 0.024 0.023 0.024 0.012 0.012 0.025 -0.029 -0.002 0.011 0.023 0.028 0.018 0.01 0.025 -0.005 41.5 116.8 264.9 352.1 310.5 224.4 149.9 106
5000 6000 61.3731847 -139.1184569 600559 6805805 843.5 56.8 164 0 -0.054 -0.073 -0.03 0.001 0.006 0.016 0.038 0.014 -0.039 -0.019 -0.01 0.008 0.018 0.019 0.04 0.014 0.009 0.024 0.022 0.02 0.008 0.011 0.014 0.018 -0.004 0.014 0.027 0.022 0.013 0.004 0.008 0.031 46.2 116.3 286.3 484.4 543.5 439.8 190.7 235.9
5000 6250 61.37478629 -139.115441 600715 6805988 839.1 281.8 222 0 -0.098 -0.007 -0.001 0.007 0.017 0.023 0.01 -0.076 -0.048 -0.03 -0.021 -0.016 -0.01 -0.023 -0.054 0.036 0.012 0.023 0.018 0.013 0.007 -0.002 -0.073 -0.023 0.011 0.015 0.012 0.006 0.001 -0.002 25.2 122.5 361.2 681.5 770.7 788.5 634.9 446.7
5000 6500 61.37649418 -139.1123249 600876 6806183 836.7 195.1 137 0 0.067 0.021 0.027 0.058 0.072 -0.035 -0.028 -0.03 -0.066 -0.088 0.018 0.001 0.016 0.018 0.019 0.012 0.003 0.011 0.002 -0.001 -0.014 -0.009 86.3 54.8 284.1 398.3 881.3 635.9 349.4 565.1
5000 6750 61.37814738 -139.1091555 601040 6806372 833.7 181.3 121 0 -0.023 -0.016 0.002 0.002 0.016 0.064 0.085 -0.019 -0.034 -0.034 -0.032 -0.036 -0.006 -0.022 -0.052 -0.014 0.018 0.02 0.017 0.017 0.043 0 -0.048 -0.024 -0.017 -0.005 -0.004 -0.002 0.008 0 58.8 147.5 416.7 731 730.8 365.3 121.4 64.5
5000 7000 61.3798031 -139.1061729 601194 6806561 830.9 357.8 178 0.1 -0.04 -0.022 -0.008 0.005 0.016 0.051 -0.025 -0.034 -0.04 -0.034 -0.029 -0.027 -0.026 -0.011 -0.004 0.008 0.019 0.026 0.03 0.077 -0.131 -0.041 -0.013 0 0.002 0.004 -0.003 0.004 24.5 109.7 323.5 838.2 1000 400.5 58.8 11.5
5000 7000 61.3798031 -139.1061729 601194 6806561 830.9 64.5 191 0 -0.056 -0.037 -0.011 -0.005 -0.001 0.014 -0.004 0.063 0.003 -0.028 -0.033 -0.026 -0.025 -0.024 -0.067 -0.06 -0.053 0.008 0.009 0.019 0.023 0.031 0.05 0.159 -0.054 -0.031 -0.013 -0.003 -0.002 0 0.003 0.149 48.4 146.6 383 656.4 498.3 194.5 101.1 76.3

johnathank · January 15, 2020, 5:48pm

Hi Alex, you are in luck, Z-Axis tipper is good to go out of the box with SimPEG. I have successfully inverted a few synthetic models using tipper only. The biggest initial hurdle will be writing an IO for your data file so that a SimPEG Survey class can be generated. I would suggest taking a look at the 3D MT forward model example. It includes both tipper setup and regular MT setup. As long as you can get your data into a SimPEG survey we should be able to guide you through to inversion. Let me know how it goes and we can discuss further.

Best,
J

jkutt85 · April 30, 2020, 9:36pm

Hi @AlexJ, I have been working away at NSEM problems and I have made a general data loader for databases like the one you provided here. This script sets up the SimPEG survey object that can be used in the inversion. It would still require a little modification in the code but most of the heavy lifting is done on that part. If you were interested I could share the code for you to develop further or at least I can guide you through it? Let me know what you think!

AlexJ · April 30, 2020, 9:58pm

John,

That is great news! I have been following along on the youtube channel.

Please share the code with me. I will see if I can make the modifications myself.

If I can’t, I will ask for more help, as I really want to start producing inversion.

I kept notes on the MT conventions that simPEG uses ( as discussed in one of weekly meetings), so I am ready to give it a go.

jkutt85 · May 6, 2020, 12:00am

Alex,

Perfect! Give me a few days to put together the script with a bit more detailed comments to help you along the way. I’m a little busy right now but I will get back to you by the end of the week.

Best,

J

jkutt85 · May 13, 2020, 5:10pm

@AlexJ, apologies for the delay, work projects have not let up all that much lately. I have attached my module for IO of NSEM data. I didn’t get to commenting as much as I’d like to help guide you but feel free to contact me on here and we can work this out. I have broken things up into a “Patch” class that hold “stations”. Also included is a tool named readDat. This is the function you will be modifying. What this does is determine the stations of the survey and then for each station assign the frequency data and whichever else you want to add. If there are some parameters that you would like include, you can modify the “mtStation” class to initiate them. The file format I have this setup for currently is a little different than your’s but not far off. Start by having a look and I will help the best I can. AMTtools.py (13.3 KB)

AlexJ · May 13, 2020, 5:53pm

John,
Thank you kindly.
I will let you know how it goes. I hope to try it out next week.

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Z-Axis Tipper Electromagnetic Ground Surveys

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