Ejecta distribution studies for large-sized (>10 km) lunar craters have been carried out earlier, but similar studies on smaller craters are lacking mainly due to data resolution limitations. Here we present a detailed quantification on spatial deposition of ejecta for small-sized lunar craters (<6 km). Using data from Mini RF instrument on-board NASA's Lunar Reconnaissance Orbiter, four Stokes parameters that differentiate and describe the observed backscattered electromagnetic field are calculated. We use the first Stokes parameter to investigate and estimate the spatial ejecta distribution for 98 small-sized fresh and degraded craters from mare and highland regions. It is observed that ejecta distribution can be described using power law with crater diameter and depth/ diameter (d/D) ratio. Ejecta behaviour is analysed for both the terrain types, highland and mare, enabling us to understand the effect and dependency of target rock properties on the ejecta characteristics. Further, the d/D dependence has indicated that the relative degradation rate appears higher for highland region compared to mare region.
ABSTRACT:Fluvial landforms are developed due to river action and these processes help in understanding the development of various landforms on the earth's surface. Gangetic plain is vast alluvial tract made up of sand, silt and clay. This region receives heavy rainfall causing flash floods which results in bank-line shifting as well as various fluvio-geomorphological changes. Fluvial processes such as erosion and deposition not only play an important role in shaping of different fluvial landscapes but also contribute towards the braiding and meandering pattern which causes change in the flow pattern of the river channel. Transportation and deposition of the suspended load also contributes towards such changes. The present work describes various fluvio-geomorphological features and their changes during different time intervals in and around Ballia and Rudrapur. The paper also deals in understanding the problems like bank-line shifting, erosion and deposition caused by the continuous change in the fluvial patterns, bank erosion and sedimentation in this region over past 8 decades.
Wind is currently the dominant active geological agent bringing about constant changes over the Martian surface. One of the most conspicuous resultant morphology derived is the formation of slope streaks, highly transient features that tend to develop and may completely disappear within a few ten of years. In this article a detailed analysis on the pattern, morphology and appearance of slope streaks within the central mound of the Nicholson crater on Mars, has been made and plausible reasons for their formation as well as darkening and fading mechanisms are discussed. We focus on some observations which indicate the role of wind in carving specific streak patterns. The morphological observations discussed, strongly support active aeolian processes and provide evidences in favour of the dust avalanche theory for the formation and current morphology of slope streaks in the Nicholson crater.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.