Sastrugi breaking equipment—ripples and waves are often undercut and the surface is hard and unforgiving, with constant minor topographic changes between ridge and trough. The words "sastrugi" and "zastrugi" are Russian-language plurals; the singular is "sastruga" or "zastruga". The form "sastruga" started as the German-language transliteration of the Russian word заструга (plural: заструги). A Latin-type analogica singular "sastrugus" is used in various writings on exploration of the South Pole, including Robert Falcon Scott's expedition's diaries and Ernest Shackleton's "The Heart of the Antarctic". Under the action of steady wind, free snow particles accumulate and drift like the sand grains in barchan
Surface features of Venus Theia Mons. In a coronae-dominated rise, uplift is caused by the gravitational collapse and extension of a magma chamber, and include the Themis Regio. Tesserae are a feature unique to Venus and are characterized as continent-sized regions of high topography (1 to >5 km above the datum) that are heavily deformed, often with complex patterns of ridges. These areas are formed by the intersection of at least two structural components. Tesserae are classified base on their structural components.Types of Tesserae Examples include Ishtar Terra and Aphrodite Terra. Tesserae are considered to be the oldest surface features on Venus because of