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  • 1
    Online Resource
    Online Resource
    Formation of shatter cones by symmetric fracture bifurcation: Phenomenological modeling and validation
    Wiley ; 2016
    In:  Meteoritics & Planetary Science Vol. 51, No. 8 ( 2016-08), p. 1519-1533
    Details
    In: Meteoritics & Planetary Science, Wiley, Vol. 51, No. 8 ( 2016-08), p. 1519-1533
    Abstract: Several models of shatter cone formation require a heterogeneity at the cone apex of high impedance mismatch to the surrounding bulk rock. This heterogeneity is the source of spherically expanding waves that interact with the planar shock front or the following release wave. While these models are capable of explaining the overall conical shape of shatter cones, they are not capable of explaining the subcone structure and the diverging and branching striations that characterize the surface of shatter cones and lead to the so‐called horse‐tailing effect. Here, we use the hierarchical arrangement of subcone ridges of shatter cone surfaces as key for understanding their formation. Tracing a single subcone ridge from its apex downward reveals that each ridge branches after some distance into two symmetrically equivalent subcone ridges. This pattern is repeated to form new branches. We propose that subcone ridges represent convex‐curved fracture surfaces and their intersection corresponds to the bifurcation axis. The characteristic diverging striations are interpreted as the intersection lineations delimiting each subcone. Multiple symmetric crack branching is the result of rapid fracture propagation that may approach the Raleigh wave speed. We present a phenomenological model that fully constructs the shatter cone geometry to any order. The overall cone geometry including apex angle of the enveloping cone and the degree of concavity (horse‐tailing) is largely governed by the convexity of the subcone ridges. Straight cones of various apical angles, constant slope, and constant bifurcation angles form if the subcone convexity is low (30°). Increasing subcone convexity leads to a stronger horse‐tailing effect and the bifurcation angles increase with increasing distance from the enveloping cone apex. The model predicts possible triples of enveloping cone angle, bifurcation angle, and subcone angle. Measurements of these quantities on four shatter cones from different impact structures and lithologies agree well with model predictions.
    Type of Medium: Online Resource
    ISSN: 1086-9379 , 1945-5100
    URL: Issue
    URL: Article
    DOI: 10.1111/maps.2016.51.issue-8
    DOI: 10.1111/maps.12677
    Language: English
    Publisher: Wiley
    Publication Date: 2016
    detail.hit.zdb_id: 2011097-2
    SSG: 16,12
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  • 2
    Online Resource
    Online Resource
    Structural uplift and ejecta thickness of lunar mare craters: New insights into the formation of complex crater rims
    Wiley ; 2017
    In:  Meteoritics & Planetary Science Vol. 52, No. 10 ( 2017-10), p. 2220-2240
    Details
    In: Meteoritics & Planetary Science, Wiley, Vol. 52, No. 10 ( 2017-10), p. 2220-2240
    Abstract: We investigate the elevated crater rims of lunar craters. The two main contributors to this elevation are a structural uplift of the preimpact bedrock and the emplacement of ejecta on top of the crater rim. Here, we focus on five lunar complex mare craters with diameters ranging between 16 and 45 km: Bessel, Euler, Kepler, Harpalus, and Bürg. We performed 5281 measurements to calculate precise values for the structural rim uplift and the ejecta thickness at the elevated crater rim. The average structural rim uplift for these five craters amounts to S RU  = 70.6 ± 1.8%, whereas the ejecta thickness amounts to E T  = 29.4 ± 1.8% of the total crater rim elevation. Erosion is capable of modifying the ratio of ejecta thickness to structural rim uplift. However, to minimize the impact of erosion, the five investigated craters are young, pristine craters with mostly preserved ejecta blankets. To quantify how strongly craters were enlarged by crater modification processes, we reconstructed the dimensions of the transient crater. The difference between the transient crater diameter and the final crater diameter can extend up to 11 km. We propose reverse faulting and thrusting at the final crater rim to be one of the main contributing factors of forming the elevated crater rim.
    Type of Medium: Online Resource
    ISSN: 1086-9379 , 1945-5100
    URL: Issue
    URL: Article
    DOI: 10.1111/maps.2017.52.issue-10
    DOI: 10.1111/maps.12925
    Language: English
    Publisher: Wiley
    Publication Date: 2017
    detail.hit.zdb_id: 2011097-2
    SSG: 16,12
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  • 3
    Online Resource
    Online Resource
    Morphometric Characterization of Longitudinal Striae on Martian Landslides and Impact Ejecta Blankets and Implications for the Formation Mechanism
    American Geophysical Union (AGU) ; 2020
    In:  Journal of Geophysical Research: Planets Vol. 125, No. 2 ( 2020-02)
    Details
    In: Journal of Geophysical Research: Planets, American Geophysical Union (AGU), Vol. 125, No. 2 ( 2020-02)
    Abstract: Longitudinal striae are scale‐invariant and can be characterized using power spectral parameters that quantify relief and roughness Striae on both types of deposits share common characteristics that indicate a common formation mechanism We propose a formation mechanism that facilitates phase locking in the spectral domain
    Type of Medium: Online Resource
    ISSN: 2169-9097 , 2169-9100
    URL: Article
    DOI: 10.1029/2019JE006255
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2020
    detail.hit.zdb_id: 1086497-0
    detail.hit.zdb_id: 3094268-8
    detail.hit.zdb_id: 2016810-X
    SSG: 16,13
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  • 4
    Online Resource
    Online Resource
    Ejecta thickness and structural rim uplift measurements of Martian impact craters: Implications for the rim formation of complex impact craters
    American Geophysical Union (AGU) ; 2016
    In:  Journal of Geophysical Research: Planets Vol. 121, No. 6 ( 2016-06), p. 1026-1053
    Details
    In: Journal of Geophysical Research: Planets, American Geophysical Union (AGU), Vol. 121, No. 6 ( 2016-06), p. 1026-1053
    Abstract: Structural rim uplift is the dominant factor to build up the total amount of the final crater rim Structural rim uplift contributes four fifths to the total elevation of crater rims Target uplift at the position of the final crater rim was established during the excavation stage
    Type of Medium: Online Resource
    ISSN: 2169-9097 , 2169-9100
    URL: Issue
    URL: Article
    DOI: 10.1002/jgre.v121.6
    DOI: 10.1002/2015JE004959
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2016
    detail.hit.zdb_id: 1086497-0
    detail.hit.zdb_id: 3094268-8
    detail.hit.zdb_id: 2016810-X
    SSG: 16,13
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  • 5
    Online Resource
    Online Resource
    Comment on “Earth and Moon impact flux increased at the end of the Paleozoic”
    American Association for the Advancement of Science (AAAS) ; 2019
    In:  Science Vol. 365, No. 6450 ( 2019-07-19)
    Details
    In: Science, American Association for the Advancement of Science (AAAS), Vol. 365, No. 6450 ( 2019-07-19)
    Abstract: Mazrouei et al . (Reports, 18 January 2019, p. 253) found a nonuniform distribution of crater ages on Earth and the Moon, concluding that the impact flux increased about 290 million years ago. We show that the apparent increase on Earth can be explained by erosion, whereas that on the Moon may be an artifact of their calibration method.
    Type of Medium: Online Resource
    ISSN: 0036-8075 , 1095-9203
    URL: Article
    DOI: 10.1126/science.aaw7471
    RVK:
    TA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: American Association for the Advancement of Science (AAAS)
    Publication Date: 2019
    detail.hit.zdb_id: 128410-1
    detail.hit.zdb_id: 2066996-3
    detail.hit.zdb_id: 2060783-0
    SSG: 11
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  • 6
    Online Resource
    Online Resource
    Long-term erosion rates as a function of climate derived from the impact crater inventory
    Copernicus GmbH ; 2019
    In:  Earth Surface Dynamics Vol. 7, No. 2 ( 2019-05-23), p. 459-473
    Details
    In: Earth Surface Dynamics, Copernicus GmbH, Vol. 7, No. 2 ( 2019-05-23), p. 459-473
    Abstract: Abstract. Worldwide erosion rates seem to have increased strongly since the beginning of the Quaternary, but there is still discussion about the role of glaciation as a potential driver and even whether the increase is real at all or an artifact due to losses in the long-term sedimentary record. In this study we derive estimates of average erosion rates on the timescale of some tens of millions of years from the terrestrial impact crater inventory. This approach is completely independent from all other methods to infer erosion rates such as river loads, preserved sediments, cosmogenic nuclides, and thermochronometry. Our approach yields average erosion rates as a function of present-day topography and climate. The results confirm that topography accounts for the main part of the huge variation in erosion on Earth, but also identifies a significant systematic dependence on climate in contrast to several previous studies. We found a 5-fold increase in erosional efficacy from the cold regimes to the tropical zone and that temperate and arid climates are very similar in this context. Combining our results into a worldwide mean erosion rate, we found that erosion rates on the timescale of some tens of millions of years are at least as high as present-day rates and suggest that glaciation has a rather regional effect with a limited impact at the continental scale.
    Type of Medium: Online Resource
    ISSN: 2196-632X
    URL: Article
    URL: Article
    DOI: 10.5194/esurf-7-459-2019
    DOI: 10.5194/esurf-7-459-2019-supplement
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2019
    detail.hit.zdb_id: 2736054-4
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