Ceraunius Tholus is a volcano on

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

located in the

Tharsis quadrangle The Tharsis quadrangle is one of a series of 30 list of quadrangles on Mars, quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Tharsis quadrangle is also referred to as MC-9 (Mars Chart- ...

at 24.25° north latitude and 262.75° east longitude, part of the Uranius group of volcanoes. It is across, approximately high and is named after a classical

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

feature name. It is generally believed to be a basaltic shield with the lower part buried beneath plain forming lavas. Earlier interpretations suggested that it is a

stratovolcano A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

. The slopes on Ceraunius Tholus are quite steep with an average slope of 8° with many radial erosion channels and pitted valleys extending from just below the rim of the

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

toward the base of the volcano. The current view is that the valleys were eroded by water. Interesting features on Ceraunius Tholus are three large canyons at the northwest flank of Ceraunius Tholus which are up to 2.5 km wide and 300 m deep. The biggest of these three also appears to be the youngest and protrude from the lowest point of the volcanic caldera and ends at the interesting crater Rahe (an oblique impact crater with measures of 35 × 18 km), just north from the volcano where it formed a depositional fan. Its origin is still debatable and there are four main models proposed: fluvial action, volcanic flows, valley being a lava channel or some combination of previously mentioned models. Ceraunius appears small compared to other larger volcanoes, but it is almost as tall as Earth's

Mount Everest Mount Everest (), known locally as Sagarmatha in Nepal and Qomolangma in Tibet, is Earth's highest mountain above sea level. It lies in the Mahalangur Himal sub-range of the Himalayas and marks part of the China–Nepal border at it ...

. The caldera of Ceranius Tholus is also dotted with many collapse pits, which are distinct from impact craters as they have no rim and vary in abundance across the caldera. Ceraunius Tholus is probably late Hesperian in age. The crater Paros lies south of Ceraunius Tholus, and the elongate crater Rahe is to the north.

Glaciers

Some scientists believe that

glaciers A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

may have existed on many of the volcanoes in Tharsis including Olympus Mons, Ascraeus Mons, and Pavonis Mons. A study analysing data gathered over Ceraunius Tholus by the

Mars Orbiter Laser Altimeter image:PIA02040 Martian hemispheres by MOLA.jpg, 260px, MOLA topographic images of the two hemispheres of Mars. This image appeared on the cover of ''Science'' magazine in May 1999. The Mars Orbiter Laser Altimeter (MOLA) was one of five instruments ...

concluded that there was likely to have been a period of significant snow and ice accumulation, and that snowmelt may have contributed to valley formation on Ceraunius Tholus, as well as the formation of a caldera lake. A subsequent study utilising high-resolution colour imagery from the Colour and Stereo Surface Imaging System onboard the ESA Trace Gas Orbiter found evidence of periodic frost formation on Ceraunius Tholus.

Environment around Ceraunius Tholus

Ceraunius Tholus is on the Tharsis rise, also called the Tharsis bulge. Tharsis is a land of great

volcanoes A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often fo ...

. Olympus Mons is the tallest known volcano. Ascraeus Mons and Pavonis Mons are at least 320 km across and are over 10 km above the

plateau In geology and physical geography, a plateau (; ; : plateaus or plateaux), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. ...

that they sit on. The plateau is five to four seven kilometers above the zero altitude of Mars.Norton, O. 2002. Mapping Mars. Picador, New York. Tharsis Quadrangle map-la

Image:Ceraunius Tholus Channel.JPG, Ceraunius Tholus Channel, as seen by HiRISE. The summit crater of Ceraunius Tholus is just to the right of this picture. Click on image to see dark slope streaks. The scale bar is 1000 meters long. Image:Cerauniustholus.jpg, View of Ceraunius Tholus and Uranius Tholus from the Mars Orbiter Camera of '' Mars Global Surveyor''. Image:Ceraunius Tholus 3D THEMIS dayIR-MOLA 5x vert.jpg, Computer-generated 3D view of Ceraunius Tholus with 5x vertical exaggeration. The image was obtained from THEMIS coverage plus MOLA altimetry. The crater Rahe is at left.

Glaciers

Environment around Ceraunius Tholus

References

See also