Venus Channelized Flow Catalog

Venus Channelized Flow Catalog (VCFC): Online database Authors: D.A. Crown and I.T.W. Flynn VCFC Description: The Venus Channelized Flow Catalog is a database that was compiled using Magellan FMAP data (left-look global mosaic; 75 m/pixel; 92% surface coverage). A systematic global survey at 1:500,000 mapping scale identified candidate channelized lava flows and recorded their locations at GIS point features. Channelized lava flows were classified on the basis of their size and the nature of their definition/exposure. Two different types of channelized lava flows were identified by their morphology and volcanic context. In Magellan radar data channelized lava flows are identified by prominent variations in radar brightness between a darker central channel and brighter lateral levees. The variation in radar brightness between the central channel and levee can be attributed to smoother flow surfaces in the central channel and rougher levee surfaces. The smoother flow surface of the central may be formed during the emplacement of the original flow or in some cases by infilling of younger flows either from the same eruption or subsequent ones. FID: Channelized lava flow ID number Point_X: Longitude of channelized lava flow location (-180 to 180 deg) Point_Y: Latitude of channelized lava flow location (-90 to 90 deg) Class: Classification of channelized lava flow based on size and nature of definition/exposure (1, 2, or 3) Class 1: Class of channelized lava flows that include generally larger examples in the catalog and/or show best definition/exposure in Magellan FMAPs. Class 2: Class of channelized lava flows that include small to medium-sized examples in the catalog and/or show moderately well-defined/exposed characteristics in Magellan FMAPs. Class 3: Class of channelized lava flows that include small examples in the catalog and/or are poorly defined/exposed in Magellan FMAPs. Type: Type of channelized lava flow based on morphology and volcanic context (a or b) Type a: Channelized lava flow (exposed central channel and lateral levees). These are generally part of flow fields with both other channelized flows and other flow types (non-channelized). Flow patterns are commonly radial or spread from inferred common source region and seem to define volcanic edifices in some cases. Type b: Vallis-type channelized lava flow. These show morphologic characteristsics of both Type a channelized lava flows and canali segments. These occur as individual features or in small (quasi-parallel) groups and can be very long. Some parts of their lengths exhibit associated flows (radar bright) or levee-like breakouts from the channel. The channels exhibit linear to sinuous segments, and the associated flows range from narrow to wide and sheet-like.