New Geological Studies and Crater Size-Frequency Distributions of Apollo Landing Sites and their Future Implications.

2021 ◽  
Author(s):  
Wajiha Iqbal ◽  
Harald Hiesinger ◽  
Carolyn van der Bogert ◽  
Thomas Heyer ◽  
Nico Schmedemann
Keyword(s):  
Frequency Distributions ◽  
Crater Size ◽  
Size Frequency ◽  
Landing Sites

scholarly journals 2.2.2 The Size Frequency Distribution and Rate of Production of Microcraters

1976 ◽  
Vol 31 ◽  
pp. 227-231
Author(s):  
D. A. Morrison ◽  
E. Zinner
Keyword(s):  
Frequency Distribution ◽  
Lunar Surface ◽  
Particle Flux ◽  
Surface Orientation ◽  
Submicron Particle ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Crater Size ◽  
Size Frequency ◽  
Micron Diameter

AbstractCrater size frequency distributions vary to a degree which probably cannot be explained by variations in lunar surface orientation of the crater detectors or changes in micrometeoroid flux. Questions of sample representativity suggest that high ratios of small to large craters of micrometeoroids (e.g., a million 1.0 micron craters for each 500 micron crater) should be the most reliable. We obtain a flux for particles producing 0.1 micron diameter craters of approximately 300 per cm2 per steradian per year. We observe no anisotropy in the submicron particle flux between the plane of the ecliptic and the normal in the direction of lunar north. No change in flux over a 106 year period is indicated by our data.

scholarly journals How old are lunar lobate scarps? 1. Seismic resetting of crater size-frequency distributions

Icarus ◽  
2018 ◽  
Vol 306 ◽  
pp. 225-242 ◽  
Author(s):  
Carolyn H. van der Bogert ◽  
Jaclyn D. Clark ◽  
Harald Hiesinger ◽  
Maria E. Banks ◽  
Thomas R. Watters ◽  
...  
Keyword(s):  
Frequency Distributions ◽  
Crater Size ◽  
Size Frequency

Detailed age determinations for Tsiolkovskiy crater floor

2021 ◽  
Author(s):  
Gloria Tognon ◽  
Sabrina Ferrari ◽  
Riccardo Pozzobon ◽  
Matteo Massironi
Keyword(s):  
Age Determination ◽  
Total Surface Area ◽  
Geological Mapping ◽  
Crater Floor ◽  
The European Union ◽  
Frequency Distributions ◽  
Horizon 2020 ◽  
Color Ratio ◽  
Crater Size ◽  
Size Frequency

<p>With respect to its counterpart, the lunar farside is characterized by few basaltic mare exposures. One of these, with a total surface area of approximately 12 000 km<sup>2</sup>, covers the floor of the ~200 km diameter Tsiolkovskiy crater (20.4° S, 129.1° E) [1].</p><p>The crater size frequency distributions (CSFDs) calculated for this crater led to different results. The age determination performed on the mare infilling resulted in an Imbrian-Erathostenian age of about 3.2 Ga [2], while a 3.6 Ga Late Imbrian age was derived from areas scattered on top of a long run-out landslide generated from the western rim and its surroundings [3-4].</p><p>The spectral map produced for Tsiolkovskiy crater [5-6], performed on the ~200 m/pixel Clementine UVVIS color ratio mosaic [7] (R: 750/415 nm; G: 750/1000 nm; B: 415/750 nm), and recently updated suggests for the crater floor the presence of three color units, characteristics of higher 415/750 nm ratio, higher 750/415 nm ratio and average 750/415 nm and 750/1000 nm ratios, defined by a different composition and/or age formation.</p><p>In order to discriminate possible age differences ascribable to different eruptive events, on the basis of the spectral mapping we defined several areas for measuring the crater size-frequency distributions of the different color units on the crater floor. In addition, we calculated the age formation of Tsiolkovskiy crater itself by means of hummocky areas interpreted as impact melt identified in accordance to the geological mapping [5-6] performed on the ~100 m/pixel LRO-WAC [8] global mosaic.</p><p>The CSFDs measurements have been performed on areas of at least 100 km<sup>2</sup> using the CraterTools add-on [9] in the ArcGIS software on LRO-NAC [8] images with resolution ranging between 0.5 and 1.5 m/pixel. The exported data have then been plotted in the Craterstats2 software [10].</p><p>The obtained results highlight that i) Tsiolkovskiy crater formed around 3.6 Ga, in agreement with [3], ii) three different age ranges are discernible and iii) these age ranges are correlated to each one of the three color units of the crater floor.</p><p>This allows to reconstruct the evolution history of the crater and in particular of its crater floor, with particular focus also on its compositional variegation.</p><p> </p><p>Acknowledgments</p><p>This research was supported by the European Union’s Horizon 2020 under grant agreement No 776276-PLANMAP.</p><p>References</p><p>[1] Whitford-Stark, J.L. & Hawke, B.R., XXXIII LPSC, pp. 861-862, 1982  [2] Pasckert, J.H. et al., Icarus, Vol. 257, pp. 336-354, 2015  [3] Boyce, J.M. et al., XXXXVII LPSC, 2471, 2016  [4] Boyce, J.M. et al., Icarus, Vol. 337, 2020  [5] Tognon, G. et al., EGU, 733, 2020  [6] Tognon, G. et al., EPSC, 581, 2020  [7] Lucey, P.G. et al., JGR, Vol. 105, pp. 20377-20386, 2000  [8] Robinson, M.S. et al., Space Sci. Rev., Vol. 150, pp. 81–124, 2010  [9] Kneissl, M. et al., Plan. Space Sci., Vol. 59, pp. 1243-1254, 2011  [10] Michael G.G. & Neukum, G., Earth and Plan. Sci. Letters, Vol. 294, pp. 223-229, 2010</p>

Origin of discrepancies between crater size-frequency distributions of coeval lunar geologic units via target property contrasts

Icarus ◽  
2017 ◽  
Vol 298 ◽  
pp. 49-63 ◽  
Author(s):  
C.H. van der Bogert ◽  
H. Hiesinger ◽  
C.M. Dundas ◽  
T. Krüger ◽  
A.S. McEwen ◽  
...  
Keyword(s):  
Frequency Distributions ◽  
Target Property ◽  
Crater Size ◽  
Size Frequency

scholarly journals Lunar mare basalt flow units: Thicknesses determined from crater size-frequency distributions

2002 ◽  
Vol 29 (8) ◽  
pp. 89-1-89-4 ◽  
Author(s):  
H. Hiesinger ◽  
J. W. Head ◽  
U. Wolf ◽  
R. Jaumann ◽  
G. Neukum
Keyword(s):  
Basalt Flow ◽  
Frequency Distributions ◽  
Mare Basalt ◽  
Flow Units ◽  
Crater Size ◽  
Size Frequency ◽  
Lunar Mare

scholarly journals Effect of Topography Degradation on Crater Size-Frequency Distributions: Implications for Populations of Small Craters and Age Dating

2017 ◽  
Vol 44 (20) ◽  
pp. 10,171-10,179 ◽  
Author(s):  
Minggang Xie ◽  
Meng-Hua Zhu ◽  
Zhiyong Xiao ◽  
Yunzhao Wu ◽  
Aoao Xu
Keyword(s):  
Age Dating ◽  
Frequency Distributions ◽  
Crater Size ◽  
Size Frequency

Revised recommended methods for analyzing crater size-frequency distributions

2018 ◽  
Vol 53 (4) ◽  
pp. 891-931 ◽  
Author(s):  
Stuart J. Robbins ◽  
Jamie D. Riggs ◽  
Brian P. Weaver ◽  
Edward B. Bierhaus ◽  
Clark R. Chapman ◽  
...  
Keyword(s):  
Frequency Distributions ◽  
Crater Size ◽  
Size Frequency

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

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