Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations

Dhananjay Ravat, Nils Olsen, Terence Sabaka, Livia Kathleen Kother, Stavros Kotsiaros, Michael Purucker

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

Abstract

Gradients of magnetic field have higher spatial resolution than the fields themselves and are helpful in improving the resolution of downward continued satellite magnetic anomaly maps (Kotsiaros et al., 2015, Geophys. J. Int.; Sabaka et al., 2015, Geophys. J. Int.). Higher spatial resolution and fidelity of the magnetic field downward continued to the Earth’s surface translate into improvements in the interpretation of anomalies for recognition of geologic variability and tectonic processes (e.g., recognizing details of geologic provinces, anomalous seafloor spreading patterns, etc., that can help understand the evolution of the Earth). Magnetic anomalies have sensitivity to thermal variations in the Earth’s lithosphere through the phenomenon of Curie temperature of ferromagnetic minerals. The response of the bottom of magnetization in the Earth’s crust/lithosphere is primarily observed in the long wavelength magnetic field up to at least 500 km (and sometimes longer). The Curie temperature depth can also be used to better map the thermal structure of the lithosphere because it is possible to theoretically include the Curie depth constraint in the derivation of the one dimensional geotherm (Ravat et al., 2015, in review). Despite having global set of observations from POGO, Magsat, Ørsted, CHAMP, and Swarm satellites (altitude > 400 km), preservation of intermediate wavelengths from about 100 to 375 km proves challenging (known as the “spectral gap”). Since the gradients of magnetic field have higher spatial resolution than the fields themselves, they are helpful in improving the coverage in the spectral gap. East-West and North-South (along orbit) gradients from Swarm magnetic field satellites provide an opportunity to examine the improvement in the anomaly coverage in the spectral gap and its effect on the interpretation, particularly the derived Curie depths and the thermal variation of the lithosphere. We examine the inaccuracies in anomalies and also their resulting interpretation using the U.S. aeromagnetic data where a full spectrum magnetic anomaly coverage is available (Ravat et al., 2009, USGS open files report OF09-1258) as a result of the availability of NURE data which were corrected with the comprehensive model of the magnetic field (CM4, Sabaka et al., 2004, Geophys. J. Int.). We specifically compare various levels and types of corrected data sets: uncorrected original North American Magnetic Anomaly Map compilation (ca. 2002), the original compilation corrected with satellite-altitude data sets, and Swarm constellation gradient corrected fields over the U.S. Using this U.S. study as a test, we examine the possibility of improving the spectral coverage in many regions of the world where anomalies and their interpretations are still affected by the spectral gap.
Original languageEnglish
Publication date2016
Number of pages1
Publication statusPublished - 2016
EventESA Living Planet Symposium 2016 - Prague, Czech Republic
Duration: 9 May 201613 May 2016
http://lps16.esa.int/

Conference

ConferenceESA Living Planet Symposium 2016
CountryCzech Republic
CityPrague
Period09/05/201613/05/2016
Internet address

Cite this

Ravat, D., Olsen, N., Sabaka, T., Kother, L. K., Kotsiaros, S., & Purucker, M. (2016). Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations. Abstract from ESA Living Planet Symposium 2016, Prague, Czech Republic.
Ravat, Dhananjay ; Olsen, Nils ; Sabaka, Terence ; Kother, Livia Kathleen ; Kotsiaros, Stavros ; Purucker, Michael . / Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations. Abstract from ESA Living Planet Symposium 2016, Prague, Czech Republic.1 p.
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abstract = "Gradients of magnetic field have higher spatial resolution than the fields themselves and are helpful in improving the resolution of downward continued satellite magnetic anomaly maps (Kotsiaros et al., 2015, Geophys. J. Int.; Sabaka et al., 2015, Geophys. J. Int.). Higher spatial resolution and fidelity of the magnetic field downward continued to the Earth’s surface translate into improvements in the interpretation of anomalies for recognition of geologic variability and tectonic processes (e.g., recognizing details of geologic provinces, anomalous seafloor spreading patterns, etc., that can help understand the evolution of the Earth). Magnetic anomalies have sensitivity to thermal variations in the Earth’s lithosphere through the phenomenon of Curie temperature of ferromagnetic minerals. The response of the bottom of magnetization in the Earth’s crust/lithosphere is primarily observed in the long wavelength magnetic field up to at least 500 km (and sometimes longer). The Curie temperature depth can also be used to better map the thermal structure of the lithosphere because it is possible to theoretically include the Curie depth constraint in the derivation of the one dimensional geotherm (Ravat et al., 2015, in review). Despite having global set of observations from POGO, Magsat, {\O}rsted, CHAMP, and Swarm satellites (altitude > 400 km), preservation of intermediate wavelengths from about 100 to 375 km proves challenging (known as the “spectral gap”). Since the gradients of magnetic field have higher spatial resolution than the fields themselves, they are helpful in improving the coverage in the spectral gap. East-West and North-South (along orbit) gradients from Swarm magnetic field satellites provide an opportunity to examine the improvement in the anomaly coverage in the spectral gap and its effect on the interpretation, particularly the derived Curie depths and the thermal variation of the lithosphere. We examine the inaccuracies in anomalies and also their resulting interpretation using the U.S. aeromagnetic data where a full spectrum magnetic anomaly coverage is available (Ravat et al., 2009, USGS open files report OF09-1258) as a result of the availability of NURE data which were corrected with the comprehensive model of the magnetic field (CM4, Sabaka et al., 2004, Geophys. J. Int.). We specifically compare various levels and types of corrected data sets: uncorrected original North American Magnetic Anomaly Map compilation (ca. 2002), the original compilation corrected with satellite-altitude data sets, and Swarm constellation gradient corrected fields over the U.S. Using this U.S. study as a test, we examine the possibility of improving the spectral coverage in many regions of the world where anomalies and their interpretations are still affected by the spectral gap.",
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Ravat, D, Olsen, N, Sabaka, T, Kother, LK, Kotsiaros, S & Purucker, M 2016, 'Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations' ESA Living Planet Symposium 2016, Prague, Czech Republic, 09/05/2016 - 13/05/2016, .

Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations. / Ravat, Dhananjay ; Olsen, Nils; Sabaka, Terence; Kother, Livia Kathleen; Kotsiaros, Stavros; Purucker, Michael .

2016. Abstract from ESA Living Planet Symposium 2016, Prague, Czech Republic.

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

TY - ABST

T1 - Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations

AU - Ravat, Dhananjay

AU - Olsen, Nils

AU - Sabaka, Terence

AU - Kother, Livia Kathleen

AU - Kotsiaros, Stavros

AU - Purucker, Michael

PY - 2016

Y1 - 2016

N2 - Gradients of magnetic field have higher spatial resolution than the fields themselves and are helpful in improving the resolution of downward continued satellite magnetic anomaly maps (Kotsiaros et al., 2015, Geophys. J. Int.; Sabaka et al., 2015, Geophys. J. Int.). Higher spatial resolution and fidelity of the magnetic field downward continued to the Earth’s surface translate into improvements in the interpretation of anomalies for recognition of geologic variability and tectonic processes (e.g., recognizing details of geologic provinces, anomalous seafloor spreading patterns, etc., that can help understand the evolution of the Earth). Magnetic anomalies have sensitivity to thermal variations in the Earth’s lithosphere through the phenomenon of Curie temperature of ferromagnetic minerals. The response of the bottom of magnetization in the Earth’s crust/lithosphere is primarily observed in the long wavelength magnetic field up to at least 500 km (and sometimes longer). The Curie temperature depth can also be used to better map the thermal structure of the lithosphere because it is possible to theoretically include the Curie depth constraint in the derivation of the one dimensional geotherm (Ravat et al., 2015, in review). Despite having global set of observations from POGO, Magsat, Ørsted, CHAMP, and Swarm satellites (altitude > 400 km), preservation of intermediate wavelengths from about 100 to 375 km proves challenging (known as the “spectral gap”). Since the gradients of magnetic field have higher spatial resolution than the fields themselves, they are helpful in improving the coverage in the spectral gap. East-West and North-South (along orbit) gradients from Swarm magnetic field satellites provide an opportunity to examine the improvement in the anomaly coverage in the spectral gap and its effect on the interpretation, particularly the derived Curie depths and the thermal variation of the lithosphere. We examine the inaccuracies in anomalies and also their resulting interpretation using the U.S. aeromagnetic data where a full spectrum magnetic anomaly coverage is available (Ravat et al., 2009, USGS open files report OF09-1258) as a result of the availability of NURE data which were corrected with the comprehensive model of the magnetic field (CM4, Sabaka et al., 2004, Geophys. J. Int.). We specifically compare various levels and types of corrected data sets: uncorrected original North American Magnetic Anomaly Map compilation (ca. 2002), the original compilation corrected with satellite-altitude data sets, and Swarm constellation gradient corrected fields over the U.S. Using this U.S. study as a test, we examine the possibility of improving the spectral coverage in many regions of the world where anomalies and their interpretations are still affected by the spectral gap.

AB - Gradients of magnetic field have higher spatial resolution than the fields themselves and are helpful in improving the resolution of downward continued satellite magnetic anomaly maps (Kotsiaros et al., 2015, Geophys. J. Int.; Sabaka et al., 2015, Geophys. J. Int.). Higher spatial resolution and fidelity of the magnetic field downward continued to the Earth’s surface translate into improvements in the interpretation of anomalies for recognition of geologic variability and tectonic processes (e.g., recognizing details of geologic provinces, anomalous seafloor spreading patterns, etc., that can help understand the evolution of the Earth). Magnetic anomalies have sensitivity to thermal variations in the Earth’s lithosphere through the phenomenon of Curie temperature of ferromagnetic minerals. The response of the bottom of magnetization in the Earth’s crust/lithosphere is primarily observed in the long wavelength magnetic field up to at least 500 km (and sometimes longer). The Curie temperature depth can also be used to better map the thermal structure of the lithosphere because it is possible to theoretically include the Curie depth constraint in the derivation of the one dimensional geotherm (Ravat et al., 2015, in review). Despite having global set of observations from POGO, Magsat, Ørsted, CHAMP, and Swarm satellites (altitude > 400 km), preservation of intermediate wavelengths from about 100 to 375 km proves challenging (known as the “spectral gap”). Since the gradients of magnetic field have higher spatial resolution than the fields themselves, they are helpful in improving the coverage in the spectral gap. East-West and North-South (along orbit) gradients from Swarm magnetic field satellites provide an opportunity to examine the improvement in the anomaly coverage in the spectral gap and its effect on the interpretation, particularly the derived Curie depths and the thermal variation of the lithosphere. We examine the inaccuracies in anomalies and also their resulting interpretation using the U.S. aeromagnetic data where a full spectrum magnetic anomaly coverage is available (Ravat et al., 2009, USGS open files report OF09-1258) as a result of the availability of NURE data which were corrected with the comprehensive model of the magnetic field (CM4, Sabaka et al., 2004, Geophys. J. Int.). We specifically compare various levels and types of corrected data sets: uncorrected original North American Magnetic Anomaly Map compilation (ca. 2002), the original compilation corrected with satellite-altitude data sets, and Swarm constellation gradient corrected fields over the U.S. Using this U.S. study as a test, we examine the possibility of improving the spectral coverage in many regions of the world where anomalies and their interpretations are still affected by the spectral gap.

M3 - Conference abstract for conference

ER -

Ravat D, Olsen N, Sabaka T, Kother LK, Kotsiaros S, Purucker M. Towards improved knowledge of geology and global thermal regime from Swarm satellites magnetic gradient observations. 2016. Abstract from ESA Living Planet Symposium 2016, Prague, Czech Republic.