Mount Morning

Coordinates: 78°30′S 163°30′E / 78.5°S 163.5°E / -78.5; 163.5
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Mount Morning
Ultra
Coordinates78°30′S 163°30′E / 78.5°S 163.5°E / -78.5; 163.5[2]
Geography
Geology
Mountain typeShield volcano
Volcanic beltMcMurdo Volcanic Group
Last eruptionUnknown[3]

Mount Morning is a

parasitic vents mainly in the form of cinder cones
dot the mountain.

The volcano was initially active during the Miocene and erupted in two separate stages with a hiatus in between. The older stage has a different chemical composition than the recent one and is heavily eroded by glaciers. The most recent parasitic vents were active about 20,000 years ago and the volcano could erupt again.

Geography and geomorphology

Mount Morning lies in

Discovery Glacier.[9] The volcano was originally described in the early to middle 20th century, before more detailed analyses took place in the 1970s, 1980s and 2000s.[10]

The volcano rises to 2,723 metres (8,934 ft) above sea level and is capped by a 4.1 by 4.9 kilometres (2.5 mi × 3.0 mi) wide

Lava flows emanate from cones and make up the present-day surface of the volcano.[15]

Mount Morning is almost entirely covered with snow and ice

lava flows and pyroclastic deposits are found in outcrops.[23] Mason Spur also contains breccias from pillow lavas, while Gandalf Ridge features a diamictite[24] and a cross-cutting fault.[25] Mason Spur was considered by Martin et al. 2021 to be a separate volcano from Mount Morning.[26]

Owing to the lack of running water,

glacial till.[29] The Vereyken Glacier descends the northeastern slopes of Mount Morning between Hurricane Ridge and Riviera Ridge. Moraines occur on these two ridges[2] and moraines dating to the Wisconsin glaciation have been reported.[30] Glaciers descending from Mount Morning feed the Koettlitz Glacier.[20] Several lakes are found on the volcano and at its foot, including Lake Morning at the end of the Riviera Ridge[8] and Lake Discovery at the foot of the Hurricane and Gandalf ridges.[10]

Topographic map of Mounts Morning and Discovery (1:250,000 scale) from USGS Mount Discovery

Geology

The

alkaline lavas during the course of the Cenozoic. It is subdivided into three provinces, the Hallett, the Melbourne and the Erebus province; Mount Morning is the southernmost volcano of the Erebus province.[5]

Mount Morning rises from a

calc-alkaline composition.[33] Tectonic sutures in this basement may have allowed magma to ascend to the surface in the Mount Morning region.[34]

Composition

clinopyroxenite, dunite, harzburgite, lherzolite, norite, pyroxenite and websterite have been reported as xenoliths.[15]

The early volcanic rocks of Mount Morning are comparable to mildly alkaline rocks from Mount Melbourne, while the more alkaline late volcanic rocks resemble these from Mount Erebus.[37] The older rocks define the "Mason Spurr lineage" while the younger ones are referred to as the "Riviera Ridge lineage".[38] Basaltic rocks are concentrated on the lower slopes, while phonolite is mainly found in the upper sector of Mount Morning.[19] The composition changes between the early and late volcanic activity of Mount Morning may be due to alteration in crustal magma processes.[29]

Eruption history

Mount Morning has been active during the

Cape Roberts[41] which go back to 24.1 million years ago. This is a long lifespan for a volcano by Antarctic standards, and may be due to tectonic factors that kept magma generation focused on Mount Morning for a long time.[42] Loading by glaciers may have influenced volcanic activity at Mount Morning.[43]

Volcanic activity has been subdivided into two phases separated by a hiatus, an early phase lasting between 11.4±0.2-18.7±0.3 million years ago and a late phase from 6.13±0.02 million years ago to almost present-day.

glaciation, while the younger ones are largely uneroded[23] and make up the present-day edifice.[15] Volcanic activity mostly occurred under the atmosphere, with the exception of some lavas that may have been erupted in a subaqueous environment[35] and hyaloclastites which have been used to infer that glaciers existed there 15.4 million years ago.[47] Volcanic activity was focused along geologic lineaments on Mount Morning, which were reused during more recent eruptions.[48]

Eruptions took place at Mount Morning about 20,000 years ago, forming well-preserved

dormant by Martin, Cooper and Dunlap 2010[49] and might be the source of tephra layers found in the area.[51]

History and name

The volcano was discovered by the Discovery Expedition in 1901-1904 and named after a relief ship that took part in the expedition.[52]

Features

Features, from north to south, include:

Gandalf Ridge

78°21′00″S 164°07′00″E / 78.35°S 164.1166667°E / -78.35; 164.1166667 A volcanic ridge at the northwest end of Hurricane Ridge, to the north of Mount Morning on Scott Coast. Gandalf is a whimsical name put forward by geologist Philip R. Kyle, Institute of Polar Studies, The Ohio State University, who examined the ridge in December 1977. The discovery of very hard volcanic rock at this ridge led to the naming: Gandalf, after a crusty character (a wizard) in J.R.R. Tolkien's Lord of the Rings.[53]

Hurricane Ridge

78°24′S 164°12′E / 78.400°S 164.200°E / -78.400; 164.200. The eastern of two broad, mainly ice-free ridges that descend north from Mount Morning. Riviera Ridge is the other, to the west, and Gandalf Ridge and Lake Discovery are located at the north end of this ridge. The name was suggested by geologist Anne C. Wright, Department of Geoscience, New Mexico Institute of Mining and Technology, a member of the NMUMT field party that camped on the ridge in the 1985–86 season. The party's tent was blown to shreds by 100-knot winds, requiring evacuation of the party by helicopter. This ridge is renowned for consistently strong winds. Juxtaposed with Riviera Ridge, which is similar in appearance to this ridge to the west.[54]

Vereyken Glacier

78°25′00″S 163°57′00″E / 78.4166667°S 163.95°E / -78.4166667; 163.95 A glacier which, together with Morning Glacier, drains the northeast slopes of Mount Morning. Vereyken Glacier flows north between Riviera Ridge and Hurricane Ridge into Koettlitz Glacier. Named by US-ACAN (1994) after Jill Vereyken, ASA manager of Field Support Services, McMurdo Station, who was active in coordination and planning of science support in Antarctica from 1984.[55]

Riviera Ridge

78°24′S 163°42′E / 78.400°S 163.700°E / -78.400; 163.700. This name has been included as a US-ACAN proposal even though it was apparently applied in about 1977 by Anne Wright (now Grassham) who worked on the ridge with P.M. Kyle. The name alludes to the warm sunny conditions experienced on the ridge in contrast to the storm conditions previously experienced on nearby "Hurricane Ridge".[56]

Testa Ridge

78°27′00″S 163°32′00″E / 78.45°S 163.5333333°E / -78.45; 163.5333333 A volcanic ridge, 2.7 nautical miles (5.0 km; 3.1 mi), extending north–south between Weidner Ridge and Riviera Ridge on the north slope of Mount Morning. Named by Advisory Committee on Antarctic Names (US-ACAN) (1994) after J. Ward Testa, biologist, University of Minnesota (later of University of Alaska); conducted seal studies during ten field seasons in McMurdo Sound and other coastal regions, 1980–94.[57]

Campbell Crag

78°27′24″S 163°32′40″E / 78.4566667°S 163.5444444°E / -78.4566667; 163.5444444 A rock peak rising to 1,918 metres (6,293 ft) high at the south end of Testa Ridge on the north slope of Mount Morning. Named by US-ACAN (1994) after Richard J. (Rick) Campbell, ASA, fixed-wing Flight Operations Coordinator at McMurdo Station, active in science support in Antarctica from 1981.[58]

Weidner Ridge

78°27′41.8″S 163°25′52.5″E / 78.461611°S 163.431250°E / -78.461611; 163.431250. A linear volcanic outcrop, approximately 4.1 kilometres (2.5 mi) long, between and parallel to Savage Ridge and Testa Ridge on the north slope of Mount Morning. Named by US-ACAN after George A. Weidner, Department of Meteorology (later Space Science and Engineering Center), University of Wisconsin. Along with Charles Stearns he developed the use of automatic weather stations in Antarctica in the period 1982–2005.[59]

Savage Ridge

78°28′52.7″S 163°22′26.5″E / 78.481306°S 163.374028°E / -78.481306; 163.374028. A linear volcanic outcrop approximately 6 kilometres (3.7 mi) long descending from the northwest slope of Mount Morning. Parallel to and about 1 kilometre (0.62 mi) from Weidner Ridge. Named by US-ACAN (1994) after Michael L. Savage, Department of Meteorology, University of Wisconsin. Along with Charles Stearns, he developed the use of automatic weather stations in Antarctica during four field seasons, 1980–86.[60]

Morning Glacier

78°28′56.5″S 163°45′45.6″E / 78.482361°S 163.762667°E / -78.482361; 163.762667. A glacier on the northeast slope of Mount Morning. The glacier flows from the peak for about 8.5 kilometres (5.3 mi), terminating partway down the mountain, approximately 8 kilometres (5.0 mi) south of

Lake Morning
, and west of the upper Vereyken Glacier. Named by US-ACAN (1994) in association with Mount Morning.[61]

Mason Spur

78°33′S 164°25′E / 78.550°S 164.417°E / -78.550; 164.417. An elevated spur, partially ice-covered and over 1,300 metres (4,300 ft) high, which projects eastward from Mount Morning. Named by US-ACAN in 1963 for Robert Mason, USARP Representative at McMurdo Station, 1962–63.[62]

References

  1. ^ a b "Antarctica Ultra-Prominences" Peaklist.org. Retrieved 2012-08-01.
  2. ^ a b c d e f Martin, Cooper & Dunlap 2010, p. 359.
  3. ^ "Morning". Global Volcanism Program. Smithsonian Institution. Retrieved 2020-03-19.
  4. ^ a b Martin & Cooper 2010, p. 515.
  5. ^ a b c Martin, Cooper & Dunlap 2010, p. 357.
  6. ^ a b Martin, Cooper & Price 2013, p. 129.
  7. ^ Paulsen & Wilson 2009, p. 1074.
  8. ^ a b LeMasurier et al. 1990, p. 124.
  9. ^ Martin et al. 2021, p. 462.
  10. ^ a b c d Martin et al. 2021, p. 463.
  11. ^ a b c d e Paulsen & Wilson 2009, p. 1072.
  12. ^ a b Smellie & Martin 2021, p. 435.
  13. ^ LeMasurier et al. 1990, p. 23.
  14. ^ Paulsen & Wilson 2009, p. 1075.
  15. ^ a b c d e f Martin, Cooper & Price 2013, p. 135.
  16. ^ Paulsen & Wilson 2009, p. 1077.
  17. ^ Paulsen & Wilson 2009, p. 1078.
  18. ^ a b Paulsen & Wilson 2009, p. 1081.
  19. ^ a b c Paulsen & Wilson 2009, p. 1073.
  20. ^ a b Christ & Bierman 2020, p. 33.
  21. ^ Martin, Cooper & Dunlap 2010, pp. 359–360.
  22. ^ Smellie & Martin 2021, p. 434.
  23. ^ a b c Martin, Cooper & Dunlap 2010, pp. 360–361.
  24. ^ a b Martin, Cooper & Dunlap 2010, p. 360.
  25. ^ Martin & Cooper 2010, p. 519.
  26. ^ Martin et al. 2021, p. 465.
  27. ^ Powell 2008, p. 1.
  28. ^ Smellie et al. 2022, p. 2.
  29. ^ a b Martin, Cooper & Dunlap 2010, p. 368.
  30. ^ Brook et al. 1995, p. 51.
  31. ^ a b Paulsen & Wilson 2009, p. 1071.
  32. ^ a b Martin, Cooper & Dunlap 2010, p. 358.
  33. ^ Martin et al. 2021, p. 449.
  34. ^ Smellie & Martin 2021, p. 420.
  35. ^ a b c Martin, Cooper & Dunlap 2010, p. 361.
  36. ^ Martin, Cooper & Dunlap 2010, pp. 361–362.
  37. ^ Martin, Cooper & Price 2013, p. 142.
  38. ^ Martin et al. 2021, p. 464.
  39. ^ Claridge & Campbell 2008, p. 71.
  40. ^ Chorley et al. 2022, p. 14.
  41. ^ Martin, Cooper & Dunlap 2010, p. 366.
  42. ^ Martin, Cooper & Dunlap 2010, p. 367.
  43. ^ Griener et al. 2015, p. 75.
  44. ^ Martin, Cooper & Dunlap 2010, p. 364.
  45. ^ Martin, Cooper & Price 2013, p. 128.
  46. ^ Smellie et al. 2022, p. 25.
  47. ^ Tingey 1982, p. 185.
  48. ^ Paulsen & Wilson 2009, p. 1083.
  49. ^ a b Martin, Cooper & Dunlap 2010, p. 369.
  50. ^ Lyon & Giggenbach 1974, p. 511.
  51. ^ Keys, Anderton & Kyle 1977, p. 993.
  52. ^ Alberts 1995, p. 505.
  53. ^ Gandalf Ridge USGS.
  54. ^ Hurricane Ridge AADC.
  55. ^ Vereyken Glacier USGS.
  56. ^ Riviera Ridge AADC.
  57. ^ Testa Ridge USGS.
  58. ^ Campbell Crag USGS.
  59. ^ Weidner RidgeAADC.
  60. ^ Savage Ridge AADC.
  61. ^ Morning Glacier AADC.
  62. ^ Alberts 1995, p. 467.

Sources

External links