Alluvial fan surface ages recorded by Landsat-8 imagery in Owens Valley, California

REMOTE SENSING OF ENVIRONMENT

卷:216

Article

D'Arcy, Mitch^1,2  Mason, Philippa J.³  Roda-Boluda, Duna C.²  Whittaker, Alexander C.³  Lewis, James M. T.³  Najorka, Jens⁴ 

[1] Univ Potsdam, Inst Earth & Environm Sci, Karl Liebknecht Str 24-25, D-14476 Potsdam, Germany

[2] GFZ German Res Ctr Geosci, Helmholtz Ctr Potsdam, D-14473 Potsdam, Germany

[3] Imperial Coll London, Dept Earth Sci & Engn, South Kensington Campus,Exhibit Rd, London SW7 2AZ, England

[4] Nat Hist Museum, Core Res Labs, Cromwell Rd, London SW7 5BD, England

关键词: Landsat-8;    Surface ages;    Surface dating;    Alluvial fans;    Southwest United States;    Owens Valley;    Geomorphology;   

DOI  :  10.1016/j.rse.2018.07.013

来源: Elsevier

【 摘 要 】

Alluvial fans are important depositional landforms that offer valuable records of terrestrial sedimentation history if their surfaces can be mapped and dated accurately. Unfortunately, as this often depends on detailed field mapping and intensive absolute dating techniques, it can be a challenging, expensive and time-consuming exercise. In this study, we demonstrate that quantitative information about the ages of alluvial fan surfaces in Owens Valley, California, is recorded by Landsat-8 multispectral satellite imagery. We show that systematic changes in the wavelength-dependent brightness of fan surfaces occur gradually over a timescale of similar to 100 kyr in this semi-arid setting, and are highly correlated with known deposit ages. Using spectro-radiometry and X-ray diffraction analysis of sediment samples collected in the field, we interpret that surface reflectance evolves primarily in response to the in-situ production of secondary illite and iron oxide by weathering in this landscape. Furthermore, we demonstrate that first-order predictions of absolute fan surface age can be derived from multispectral imagery when an initial age calibration is available. These findings suggest that multispectral imagery, such as Landsat data, can be used (i) for preliminary mapping of alluvial fans prior to detailed field work and before choosing sampling sites for conventional dating techniques, and (ii) to extend age models to undated neighbouring surfaces with equivalent physical properties, once an age-brightness calibration has been established.

【 授权许可】

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