Mount Maat [2] ( lat. Maat Mons ) is the highest Venusian volcano and the second highest elevation of the planet. Named after the ancient Egyptian goddess of truth and justice, Ma'at . Located in the Atly region next to Mount Uzza and Mount Ongvuti ; the coordinates of the center are [3]
| Mount Maat | |
|---|---|
| lat Maat mons | |
 Computer-generated image of Mount Maat. The vertical scale is 22.5 times larger than the horizontal. | |
| Specifications | |
| Volcano shape | Shield volcano |
| Crater Diameter | 28,000 × 31,000 m |
| Highest point | |
| Absolute height | 8330 [1] m |
| Location | |
| Heavenly body | Venus |
Content
Description
Mount Maat rises almost 5 km above the surrounding area [4] and 8.8 km [5] (according to other sources, 8.3 km [6] [7] ) above the average surface level of Venus. This makes it the second highest elevation of Venus after the Maxwell Mountains (which exceed it by more than a kilometer) [8] , and the highest volcano on the planet. The atmospheric pressure at the top of Mount Maat is 40% lower than at the average surface level, and is 55 bar [6] .
Mount Maat is a shield volcano hundreds of kilometers in diameter with very gentle slopes (on average 1.25 °) [6] . These slopes are covered with solidified lava flows up to 400 km long [6] . At the top of the mountain is a caldera measuring 28 × 31 km, inside which there are at least five craters with a diameter of 5-10 km. Along the southeastern slope of the volcano, a series of small (3-5 km) craters continues for approximately 40 km. This is probably the result not of an eruption, but of collapse: on the radar images of the Magellan apparatus with a resolution of 75 m / pixel, no elevations are visible around these craters [1] .
Most of the mountains of Venus in radar images look brighter than the surroundings (which is primarily explained by the formation of some well- conducting substances at low temperatures) [9] . Mount Maat is the most notable exception to this rule: it is quite dark compared to other mountains of the same or even lower height. It is possible that a coating of radioactive substances was recently flooded with lava, covered with ash or could not form due to the peculiarities of the chemical composition of the surface [10] .
The largest gravitational anomaly of Venus is connected with Mount Maat and the neighboring Mount Uzza : gravitational acceleration there is increased by 0.27 Gal . The height there also reaches the height of the Venusian geoid [11] .
Volcanic activity
Modern activity near Mount Maat has not been recorded, but there are a number of signs that it has erupted relatively recently. This is the absence of impact craters on its slopes, an exceptionally high altitude (which may mean the presence of a mantle plume supporting it) and the absence of a radio-bright coating unusual for the Venusian mountains (it may not have had time to form since the last eruption). The time required for such a coating to appear is unknown; according to a number of assumptions, it is measured in tens or hundreds of millions of years [6] .
On the slopes of the mountain, not only lava flows are visible (with sharp boundaries and average brightness in radar images): on the northern slope there is a large dark stream with blurry borders. It is interpreted as deposits left by the pyroclastic flow during the Plinian eruption of the mountain [6] .
There is an assumption that it was the eruption of Mount Maat that caused strong fluctuations in the concentration of sulfur dioxide and methane in the lower and middle atmosphere of Venus , detected by the Pioneer-Venus-1 and Pioneer-Venus-2 probes in the 1980s [6] .
See also
- The list of mountains on Venus
- Volcanism on Venus
Notes
- ↑ 1 2 Mouginis-Mark PJ Morphology of Venus Calderas: Sif and Maat Montes (unknown) // Abstracts of the 25th Lunar and Planetary Science Conference, held in Houston, TX, March 14-18, 1994 .-- 1994 . 949 . - .
- ↑ Burba G.A. Venus. Russian transcription of names . Laboratory of Comparative Planetology GEOCHI (May 2005). Date of treatment July 14, 2013.
- ↑ Maat Mons . Gazetteer of Planetary Nomenclature . International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN) (October 1, 2006). Date of treatment July 4, 2013. Archived July 6, 2013.
- ↑ PIA00106: Venus - 3D Perspective View of Maat Mons Planetary Photojournal . Jet Propulsion Lab (August 1, 1996). Date of treatment July 4, 2013. Archived July 6, 2013.
- ↑ Lazarev E.N. Map of the relief of Venus . State Astronomical Institute. P.K.Sternberg (2012). - (altitude reading from the level of 6051.8 km). Date of treatment October 28, 2013.
- ↑ 1 2 3 4 5 6 7 Robinson CA, Thornhill GD, Parfitt EA Large-scale volcanic activity at Maat Mons: Can this explain fluctuations in atmospheric chemistry observed by Pioneer Venus? (English) // Journal of Geophysical Research: journal. - 1995. - Vol. 100 , no. E6 . - P. 11755-11763 . - DOI : 10.1029 / 95JE00147 . - .
- ↑ Recalculated from the conditional sphere with a radius of 6051.0 km to 6051.8 km (current value of the average radius of Venus)
- ↑ Kaula WM, Bindschadler DL, Grimm RE, Smrekar SE, Roberts KM Styles of deformation in Ishtar Terra and their implications (Eng.) // Journal of Geophysical Research: journal. - 1992. - Vol. 97 , no. E10 . - P. 16085-16120 . - DOI : 10.1029 / 92JE01643 . - .
- ↑ Treiman AH Geochemistry of Venus' Surface: Current Limitations as Future Opportunities // Exploring Venus as a Terrestrial Planet / LW Esposito, ER Stofan and TE Cravens. - John Wiley & Sons, 2007. - P. 7–22. - 225 p. - ISBN 9781118666227 . - DOI : 10.1029 / 176GM03 .
- ↑ Campbell BA, Arvidson RE, Shepard MK, Brackett RA Remote Sensing of Surface Processes // Venus II: geology, Geophysics, Atmosphere, and Solar Wind Environment / SW Bougher, DM Hunten, RJ Phillips. - University of Arizona Press, 1997 .-- P. 518-522. - 1362 p. - ISBN 0-8165-1830-0 .
- ↑ Wieczorek MA The gravity and topography of the terrestrial planets // Treatise on Geophysics / Volume editor T. Spohn, editor-in-chief Gerald Schubert. - Elsevier, 2007 .-- Vol. 10. Planets and Moons. - P. 165–206. - 656 p. - ISBN 978-0-444-53465-1 . - DOI : 10.1016 / B978-044452748-6 / 00156-5 .