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Modern scholarship has determined that in early AD 536 (or possibly late 535), an eruption ejected massive amounts of sulfate aerosols into the atmosphere, which reduced the solar radiation reaching the Earth's surface and cooled the atmosphere for several years. In March 536, Constantinople began experiencing darkened skies and lower temperatures.
For computational reasons, astronomical year numbering and the ISO 8601 standard designate years so that AD 1 = year 1, 1 BC = year 0, 2 BC = year −1, etc. [c] In common usage, ancient dates are expressed in the Julian calendar, but ISO 8601 uses the Gregorian calendar and astronomers may use a variety of time scales depending on the ...
Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, [ 1 ] [ 2 ] which distinguishes it from slope movement .
Erosional submarine canyons slope downward and lead to alluvial fan valleys with increasing depth. [2] It is in this zone that sediment is deposited, forming the continental rise. Alluvial fans such as the Bengal Fan, which stretches 3,000 kilometers (1,900 miles), make up one of the largest sedimentary structures in the world. [1]
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of the ocean is very deep, where the seabed is known as the abyssal plain. Seafloor spreading creates ...
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
The observation was made by Ormonde de Kay in a 1973 tongue-in-cheek paper, which he introduced as "another earth-shaking new theory derived from simply looking at maps." [ 1 ] It satirizes the acceptance of plate tectonics theory as it was being formulated and refined at the time to describe the movement of the Earth's continents that is now ...
Panhole: a shallow depression or basin eroded into flat or gently sloping, cohesive rock. [2] Collapse-related: Sinkhole: a depression formed as a result of the collapse of rocks lying above a hollow. This is common in karst regions. Kettle: a shallow, sediment-filled body of water formed by melting glacial remnants in terminal moraines. [3]