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<div>The USGS Geomagnetism Program's Adjusted Data (aka "Provisional" by INTERMAGNET) provides near real time absolutely calibrated and geographically oriented geomagnetic observations. These calibration parameters are updated on the first of each month in
order to satisfy geomagnetic observatory standards for accuracy and quality control. Updates are deployed at midnight UTC, and may result in noticeable baseline shifts for observatories whose sensor response characteristics may have changed substantially since
the last such update, or in rare cases, whose actual sensor has been altered or replaced since the last update. To view the results of this month's update, go to:
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<div><a href="https://geomag.usgs.gov/plots/?timeRangeType=custom&endTime=2021-06-01T00:30:00.000Z&startTime=2021-05-31T23:30:00.000Z&type=adjusted" title="https://geomag.usgs.gov/plots/?timeRangeType=custom&endTime=2021-06-01T00:30:00.000Z&startTime=2021-05-31T23:30:00.000Z&type=adjusted">https://geomag.usgs.gov/plots/?timeRangeType=custom&endTime=2021-06-01T00:30:00.000Z&startTime=2021-05-31T23:30:00.000Z&type=adjusted</a></div>
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<div>Noteworthy issues to report in this notice:<br>
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<li>Guam <b>(GUA) Adjusted data processing was re-enabled</b> after being offline for several months. Vector magnetic measurements have stabilized, and sufficient absolute calibration measurements have been made since an unexplained baseline shift on 19 April
to warrant re-activating the Adjusted processing stream.<br>
</li><li>Deadhorse <b>(DED) Adjusted data processing remains offline</b> because no reliable calibration measurements have been made for approximately 14 months due COVID19-related changes in industry partner operations.</li><li>Shumagin <b>(SHU) experienced a moderate baseline shift</b> in its horizontal magnetic vector components on 15 May due to a small (M3.6) earthquake centered approximately 70km south of Sand Point, Alaska. This was subsequent to an even smaller earthquake-induced
shift on 24 April that was not mentioned in our previous notice.<br>
</li></ul>
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