Remote Predictive Mapping of the Tunnunik Impact Structure in the Canadian Arctic using Multispectral and Polarimetric SAR Data Fusion

Choe, Byung-Hun; Tornabene, L. L.; Osinski, G. R.; Newman, J. D.

doi:10.1080/07038992.2018.1544846

Cited by 5 publications

(3 citation statements)

References 49 publications

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“…The conductive material corresponds to the sand formations either originated from fluvioglacial processes (Choe et al. ) or deposited by sea level variations during the Quaternary era (Fig. B).…”

Section: Results and Interpretationmentioning

confidence: 99%

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Geophysical signature of the Tunnunik impact structure, Northwest Territories, Canada

Quesnel

Zylberman

Rochette

et al. 2020

Meteorit & Planetary Scien

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In 2011, the discovery of shatter cones confirmed the 28 km diameter Tunnunik complex impact structure, Northwest Territories, Canada. This study presents the first results of ground-based electromagnetic, gravimetric, and magnetic surveys over this impact structure. Its central area is characterized by a~10 km wide negative gravity anomaly of about 3 mGal amplitude, roughly corresponding to the area of shatter cones, and associated with a positive magnetic field anomaly of~120 nT amplitude and 3 km wavelength. The latter correlates well with the location of the deepest uplifted strata, an impact-tilted Proterozoic dolomite layer of the Shaler Supergroup exposed near the center of the structure and intruded by dolerite dykes. Locally, electromagnetic field data unveil a conductive superficial formation which corresponds to an 80-100 m thick sand layer covering the impact structure. Based on the measurements of magnetic properties of rock samples, we model the source of the magnetic anomaly as the magnetic sediments of the Shaler Supergroup combined with a core of uplifted crystalline basement with enhanced magnetization. More classically, the low gravity signature is attributed to a reduction in density measured on the brecciated target rocks and to the isolated sand formations. However, the present-day fractured zone does not extend deeper than~1 km in our model, indicating a possible 1.5 km of erosion since the time of impact, about 430 Ma ago. PLAIN LANGUAGE SUMMARYThis study reveals the geophysical signature of the buried structure of an eroded impact crater, Tunnunik, located in Northwest Territories, Canada. A positive magnetic anomaly was detected at the center, showing the uplift of some deep geological formations and the possible presence of strongly magnetized basement. A negative gravimetric anomaly is also observed, mostly corresponding to the fracturing/brecciation of the impacted rocks inside the crater. Using numerical models constrained by laboratory measurements on rock samples, the physical properties and geometry of the buried geological formations are estimated. An important implication of this study is the link between the geophysical remains of an impact crater and the postimpact erosion. KEY POINTSA 3 mGal negative gravity anomaly and a 120 nT positive magnetic anomaly were measured over the center of the Tunnunik impact structure. A numerical model constrained by laboratory measurements on rock samples suggests an uplifted magnetic crystalline basement. The fracturing/brecciation extends down to 1 km in depth.

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Section: Results and Interpretationmentioning

confidence: 99%

“…By using remote sensing and sample analyses, this formation was recently mapped as fluvioglacial deposits (Unit 1 of Choe et al. ). Sea shells were found in some outcrops of this formation, suggesting that it could correspond to postglacial marine deltaic deposits, now overwater due to the isostatic rebound.…”

Section: Geological Contextmentioning

confidence: 99%

Geophysical signature of the Tunnunik impact structure, Northwest Territories, Canada

Quesnel

Zylberman

Rochette

et al. 2020

Meteorit & Planetary Scien

View full text Add to dashboard Cite

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“…PALSAR data were used to detect linear structures (faults and fractures) and curvilinear structures (back-slope and dip). Choe et al [11] discussed the application of the roughness characteristics provided by SAR data in assisting the geological mapping of ASTER and Landsat-8 data. Pour et al [12] combined Hyperion and SAR data to enable the identification of hydrothermal alteration rocks by textural variations in outcrop and surface roughness.…”

Section: Introductionmentioning

confidence: 99%

Improvement of Lithological Mapping Using Discrete Wavelet Transformation from Sentinel-1 SAR Data

Guo

Yang

et al. 2022

Remote Sensing

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Lithological mapping using dual-polarization synthetic aperture radar (SAR) data is limited by the low classification accuracy. In this study, we extract ten parameters (backscatter coefficients and polarization decomposition parameters) from the Sentinel-1 dual-pol SAR data. Using 94 mother wavelet functions (MF), a one-level two-dimensional discrete wavelet transform (DWT) is applied to all the parameters, and the suitable MF is screened by comparing the overall accuracy and F1 score. Finally, the lithological mapping of the study area is performed. According to the cross-validation results, DWT can improve the overall accuracy for all MF. Db13 improved the overall accuracy by 6.1% (from 49.5% to 55.6%). The F1 score of granitoids improved by 0.223. Among the five rock units, Grantoids and Quaternary alluvium and sediment with finer gravel can be better differentiated than the other three rock units. The overall accuracy of effusive rocks (marine basic volcanic rocks) is not improved by DWT, but this study confirms the great potential of DWT in lithology classification.

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Direct Polarimetric Image Sensor and Wide Spectral Response Based on Quasi‐1D Sb₂S₃ Nanowire

Zhao

Yang

Zhong

et al. 2020

Adv Funct Materials

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Polarized photodetectors with wide spectral detection and ultra‐fast photoresponses based on anisotropic semiconductors have potential applications in military and civilian fields and have been widely studied in recent years. The dual advantages of low‐symmetry crystal structure and special electronic band‐structure make Sb2S3 the perfect choice for polarized photodetection. In this work, the optical, vibrational, and optoelectronic anisotropy of the high‐quality orthorhombic Sb2S3 nanowires are systematically investigated by experimental and theoretical studies. The metal‐semiconductor‐metal photodetectors based on a single Sb2S3 nanowire exhibit good polarization sensitivity in a broadband range from ultraviolet to near‐infrared (360 to 1550 nm) and the obtained maximum dichroic ratio is 2.54 at 638 nm. The polarization‐sensitive photocurrent mapping results show that the photocurrent is mainly derived from the Schottky junction at the interface between Au and Sb2S3. The effective separation of the photo‐generated carriers near the Schottky junction gives a photodetector response time of 470 µs. The direct polarimetric imaging demonstrates that the gray value of the image obtained by the imaging system is sensitive to the object's polarized direction. This natural sensitivity of the Sb2S3‐based photodetector to polarized objects makes it possible to image polarized objects directly as an image sensor.

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Remote Predictive Mapping of the Tunnunik Impact Structure in the Canadian Arctic using Multispectral and Polarimetric SAR Data Fusion

Cited by 5 publications

References 49 publications

Geophysical signature of the Tunnunik impact structure, Northwest Territories, Canada

Geophysical signature of the Tunnunik impact structure, Northwest Territories, Canada

Improvement of Lithological Mapping Using Discrete Wavelet Transformation from Sentinel-1 SAR Data

Direct Polarimetric Image Sensor and Wide Spectral Response Based on Quasi‐1D Sb₂S₃ Nanowire

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Remote Predictive Mapping of the Tunnunik Impact Structure in the Canadian Arctic using Multispectral and Polarimetric SAR Data Fusion

Cited by 5 publications

References 49 publications

Geophysical signature of the Tunnunik impact structure, Northwest Territories, Canada

Geophysical signature of the Tunnunik impact structure, Northwest Territories, Canada

Improvement of Lithological Mapping Using Discrete Wavelet Transformation from Sentinel-1 SAR Data

Direct Polarimetric Image Sensor and Wide Spectral Response Based on Quasi‐1D Sb2S3 Nanowire

Contact Info

Product

Resources

About

Direct Polarimetric Image Sensor and Wide Spectral Response Based on Quasi‐1D Sb₂S₃ Nanowire