Earth:Aso Caldera

From HandWiki
Short description: Caldera in Kumamoto Prefecture, Japan
Aso Caldera
Aso Volcano, Asosan
Aso Caldera 3D 2012.jpg
Aso Caldera
Highest point
PeakTakadake, [ ⚑ ] 32°53′03″N 131°06′14″E / 32.88417°N 131.10389°E / 32.88417; 131.10389
Elevation1,592 m (5,223 ft)
Coordinates [ ⚑ ] : 32°53′02″N 131°06′14″E / 32.884°N 131.104°E / 32.884; 131.104 [1]
Dimensions
Length25 km (16 mi) NS
Width18 km (11 mi) EW
Naming
Native name阿蘇カルデラ  (Japanese)
Geography
Aso Caldera is located in Japan
Aso Caldera
Aso Caldera
Kumamoto, Japan
CountryJapan
StateKumamoto Prefecture
RegionAso District, Aso City, Takamori
Geology
Age of rockPleistocene onwards
Mountain typeCaldera
Somma volcano
Type of rockDacite, Andesite[2]
Last eruption2021 CE[3]
Aerial view of Aso Caldera
Central cones of Aso volcano from their north east
Central cones of Aso volcano as seen from the north.
Central cones of Aso volcano as seen from the south near Takamori
View of the Central cones of Aso volcano with Nakadake steaming

Aso caldera (also known as Asosan, the Aso Volcano or Mount Aso, although the later term usually is used related to its currently active vents) is a geographical feature of Kumamoto Prefecture, Japan. It stretches 25 kilometers north to south and 18 kilometers east to west. The central core "Aso Gogaku" is the five major mountains in the area. Aso valley (Asodani) runs along the northern base of Mount Aso and Nango valley (Nangodani) along the south. According to research of caldera sediment, lakes used to exist in these valleys. The dried up lake areas have come to be called Old Aso Lake, Kugino Lake, and Aso Valley Lake. The Kikuchi, Shirakawa and Kurokawa rivers now drain the caldera.[4]

Geology

Within the caldera are more than 17 cones.[5] The central "Aso Gogaku" group of volcanoes are Takadake (Mount Taka) at 1,592 m (5,223 ft), Nekodake at 1,433 m (4,701 ft), Nakadake (Mount Naka) at 1,506 m (4,941 ft), Kijimadake at 1,321 m (4,334 ft) and Eboshidake at 1,337 m (4,386 ft).[4] These are higher than the caldera rim itself that towards the south west is 1,236 m (4,055 ft) high.[2] Other volcanic features include Kishimadake (Mount Kishima), Kusasenrigahama, Komezuka, a scoria cone, Ikenokubo maar, a tuff ring and Takanooban, a lava dome.[4] The currently active Nakadake has seven craters roughly aligned in a north–south direction with most recent eruptions being from the northernmost first crater of Nakadake which has hydrothermal reservoirs beneath it at about 1 km (0.62 mi) to 2.5 km (1.6 mi) depth.[5] Presently there is a roughly spherical magma chamber at a depth of 6 km (3.7 mi), and flattened at 10 km (6.2 mi) located between Kishimadake, Eboshidake, and Nakadake with the magmatic source beneath the center of Aso caldera.[5] Magma migrates diagonally upward from approximately 17 km (11 mi) depth through a northward-dipping magma-filled crack propagation zone, then into the shallow magma reservoirs mentioned already and during eruptions into an upright crack intrusion zone at 2–4 km (1.2–2.5 mi) depth.[6] There are many geothermal areas including centrally the Jigoku or "hell" Onsen and Tarutama hot springs and in the northern part, the Uchinomaki hot springs.[4]

Formation

Immediate impact of the Aso Caldera forming eruption. The pink pyroclastic flow although sterilising was modified by landforms more than this figure suggests, but 15 cm tephra contour did have significant impact on all higher life forms.

The caldera formed from four major pyroclastic flow events which occurred between 90,000 and 270,000 years ago. The largest of these was the fourth, which reached as far as nearby Yamaguchi Prefecture 160 kilometers away. The fourth eruption left a massive pyroclastic plateau which is what remains even today. In 1985 it was discovered that volcanic ash from the fourth eruption covered much of the Japanese islands. The eruptive volume of the fourth eruption is estimated to be 384 km3 (92 cu mi) dense-rock equivalent (DRE).[7] Ashfall deposit greater than 15 cm (5.9 in) deep was identified on Hokkaido Island about 1,500 km (930 mi) to the north.[6]

Nekodake, the most western Central cone within the Aso Caldera

Eruptions

<timeline> ImageSize = width:220 height:1000 PlotArea = right:50 top:10 left:50 bottom:10 DateFormat = yyyy TimeAxis = orientation:vertical Period = from:450 till:2050 AlignBars = early ScaleMajor = unit:year increment:50 start:450 Colors = 

 id:canvas value:rgb(1,1,0.85)

BackgroundColors = canvas:canvas PlotData = 

 width:15 color:white
 bar:test from:450 till:2050 #

PlotData = 

 at:2050 shift:(10,-2) fontsize:XS text:Aso eruptions since written records
 at:2040 shift:(10,-2) fontsize:XS text:(Nakadake unless noted otherwise)
 bar:test at:490 mark:(line,pink)
 bar:test at:553 mark:(line,pink)
 bar:test at:782 mark:(line,pink)
 bar:test at:825 mark:(line,pink)
 bar:test at:840 mark:(line,pink)
 bar:test at:864 mark:(line,pink)
 bar:test at:867 mark:(line,pink)
 bar:test at:1230 mark:(line,pink)
 bar:test at:1239 mark:(line,pink)
 bar:test at:1240 mark:(line,pink)
 bar:test at:1265 mark:(line,pink)
 bar:test at:1269 mark:(line,pink)
 bar:test at:1271 mark:(line,pink)
 bar:test at:1272 mark:(line,pink)
 bar:test at:1273 mark:(line,pink)
 bar:test at:1274 mark:(line,red)
 at:1274 shift:(10,-2) fontsize:XS text:1274 Damage to fields
 bar:test at:1281 mark:(line,pink)
 bar:test at:1286 mark:(line,pink)
 bar:test at:1305 mark:(line,pink)
 bar:test at:1324 mark:(line,pink)
 bar:test at:1331 mark:(line,pink)
 bar:test at:1335 mark:(line,red)
 at:1335 shift:(10,-2) fontsize:XS text:7 Feb and 26 March 1335 building damage
 bar:test at:1340 mark:(line,pink)
 bar:test at:1343 mark:(line,pink)
 bar:test at:1346 mark:(line,pink)
 bar:test at:1347 mark:(line,pink)
 bar:test at:1348 mark:(line,pink)
 bar:test at:1349 mark:(line,pink)
 bar:test at:1350 mark:(line,pink)
 bar:test at:1351 mark:(line,pink)
 bar:test at:1352 mark:(line,pink)
 bar:test at:1353 mark:(line,pink)
 bar:test at:1354 mark:(line,pink)
 bar:test at:1355 mark:(line,pink)
 bar:test at:1356 mark:(line,pink)
 bar:test at:1357 mark:(line,pink)
 bar:test at:1358 mark:(line,pink)
 bar:test at:1359 mark:(line,pink)
 bar:test at:1360 mark:(line,pink)
 bar:test at:1361 mark:(line,pink)
 bar:test at:1362 mark:(line,pink)
 bar:test at:1363 mark:(line,pink)
 bar:test at:1364 mark:(line,pink)
 bar:test at:1365 mark:(line,pink)
 bar:test at:1366 mark:(line,pink)
 bar:test at:1367 mark:(line,pink)
 bar:test at:1368 mark:(line,pink)
 bar:test at:1369 mark:(line,pink)
 bar:test at:1375 mark:(line,pink)
 bar:test at:1376 mark:(line,pink)
 bar:test at:1387 mark:(line,pink)
 bar:test at:1388 mark:(line,pink)
 bar:test at:1434 mark:(line,pink)
 bar:test at:1438 mark:(line,pink)
 bar:test at:1473 mark:(line,pink)
 bar:test at:1485 mark:(line,pink)
 bar:test at:1505 mark:(line,pink)
 bar:test at:1506 mark:(line,pink)
 bar:test at:1522 mark:(line,pink)
 bar:test at:1533 mark:(line,pink)
 bar:test at:1542 mark:(line,pink)
 bar:test at:1558 mark:(line,pink)
 bar:test at:1559 mark:(line,pink)
 bar:test at:1562 mark:(line,pink)
 bar:test at:1573 mark:(line,pink)
 bar:test at:1574 mark:(line,pink)
 bar:test at:1576 mark:(line,pink)
 bar:test at:1582 mark:(line,pink)
 bar:test at:1583 mark:(line,pink)
 bar:test at:1584 mark:(line,red)
 at:1584 shift:(10,-2) fontsize:XS text:1584 agricultural land damage
 bar:test at:1587 mark:(line,pink)
 bar:test at:1592 mark:(line,pink)
 bar:test at:1598 mark:(line,pink)
 bar:test at:1611 mark:(line,pink)
 bar:test at:1612 mark:(line,pink)
 bar:test at:1613 mark:(line,pink)
 bar:test at:1620 mark:(line,pink)
 bar:test at:1631 mark:(line,pink)
 bar:test at:1637 mark:(line,pink)
 bar:test at:1649 mark:(line,pink)
 bar:test at:1668 mark:(line,pink)
 bar:test at:1675 mark:(line,pink)
 bar:test at:1683 mark:(line,pink)
 bar:test at:1691 mark:(line,red)
 bar:test at:1708 mark:(line,pink)
 bar:test at:1709 mark:(line,pink)
 bar:test at:1765 mark:(line,red)
 at:1772 shift:(10,-2) fontsize:XS text:1772 crop damage
 bar:test at:1772 mark:(line,red)
 bar:test at:1773 mark:(line,pink)
 bar:test at:1774 mark:(line,pink)
 bar:test at:1775 mark:(line,pink)
 bar:test at:1776 mark:(line,pink)
 bar:test at:1777 mark:(line,pink)
 bar:test at:1778 mark:(line,pink)
 bar:test at:1779 mark:(line,pink)
 bar:test at:1780 mark:(line,red)
 bar:test at:1781 mark:(line,pink)
 bar:test at:1782 mark:(line,pink)
 bar:test at:1783 mark:(line,pink)
 bar:test at:1784 mark:(line,pink)
 bar:test at:1785 mark:(line,pink)
 bar:test at:1786 mark:(line,pink)
 bar:test at:1787 mark:(line,pink)
 bar:test at:1788 mark:(line,pink)
 bar:test at:1804 mark:(line,pink)
 bar:test at:1806 mark:(line,pink)
 bar:test at:1814 mark:(line,pink)
 bar:test at:1815 mark:(line,red)
 bar:test at:1816 mark:(line,magenta)
 at:1816 shift:(10,-2) fontsize:XS text:July 1816 Yunotani Onsen Disaster 1 dead
 bar:test at:1826 mark:(line,red)
 bar:test at:1827 mark:(line,red)
 bar:test at:1828 mark:(line,red)
 bar:test at:1830 mark:(line,pink)
 bar:test at:1830 mark:(line,red)
 bar:test at:1832 mark:(line,pink)
 bar:test at:1837 mark:(line,pink)
 bar:test at:1838 mark:(line,pink)
 bar:test at:1854 mark:(line,magenta)
 at:1854 shift:(10,-2) fontsize:XS text:26 February 1854 3 killed
 bar:test at:1856 mark:(line,pink)
 bar:test at:1872 mark:(line,magenta)
 at:1872 shift:(10,-2) fontsize:XS text:30 December 1872 Sulfur miners killed
 bar:test at:1873 mark:(line, pink)
 bar:test at:1874 mark:(line,pink)
 bar:test at:1884 mark:(line,pink)
 bar:test at:1894 mark:(line,red)
 bar:test at:1897 mark:(line,pink)
 bar:test at:1906 mark:(line,pink)
 bar:test at:1907 mark:(line,pink)
 bar:test at:1908 mark:(line,pink)
 bar:test at:1910 mark:(line,pink)
 bar:test at:1911 mark:(line,pink)
 bar:test at:1912 mark:(line,pink)
 bar:test at:1916 mark:(line,pink)
 bar:test at:1918 mark:(line,pink)
 bar:test at:1919 mark:(line,pink)
 bar:test at:1920 mark:(line,pink)
 bar:test at:1923 mark:(line,pink)
 bar:test at:1926 mark:(line,pink)
 bar:test at:1927 mark:(line,red)
 at:1927 shift:(10,-2) fontsize:XS text:1927-1929 crop & livestock damage
 bar:test at:1928 mark:(line,red)
 bar:test at:1929 mark:(line,red)
 bar:test at:1930 mark:(line,pink)
 bar:test at:1932 mark:(line,red)
 bar:test at:1933 mark:(line,red)
 bar:test at:1934 mark:(line,pink)
 bar:test at:1935 mark:(line,pink)
 bar:test at:1936 mark:(line,pink)
 bar:test at:1937 mark:(line,pink)
 bar:test at:1939 mark:(line,pink)
 bar:test at:1940 mark:(line,red)
 bar:test at:1941 mark:(line,pink)
 bar:test at:1942 mark:(line,pink)
 bar:test at:1943 mark:(line,red)
 bar:test at:1944 mark:(line,pink)
 bar:test at:1945 mark:(line,pink)
 bar:test at:1946 mark:(line,red)
 bar:test at:1947 mark:(line,magenta)
 at:1947 shift:(10,-8) fontsize:XS text:May 1947 crop & livestock damage
 bar:test at:1948 mark:(line,pink)
 bar:test at:1949 mark:(line,red)
 bar:test at:1950 mark:(line,pink)
 bar:test at:1951 mark:(line,pink)
 at:1953 shift:(10,-6) fontsize:XS text:27 April 1953 6 killed, crop damage
 bar:test at:1953 mark:(line,magenta)
 bar:test at:1954 mark:(line,pink)
 bar:test at:1955 mark:(line,pink)
 bar:test at:1956 mark:(line,pink)
 bar:test at:1957 mark:(line,pink)
 bar:test at:1958 mark:(line,magenta)
 at:1958 shift:(10,-4) fontsize:XS text:24 June 1958 12 killed, building damage
 bar:test at:1959 mark:(line,pink)
 bar:test at:1960 mark:(line,pink)
 bar:test at:1961 mark:(line,pink)
 bar:test at:1962 mark:(line,pink)
 bar:test at:1963 mark:(line,pink)
 bar:test at:1964 mark:(line,pink)
 bar:test at:1965 mark:(line,red)
 at:1965 shift:(10,-1) fontsize:XS text:31 October 1965 building damage
 bar:test at:1966 mark:(line,pink)
 bar:test at:1967 mark:(line,pink)
 bar:test at:1968 mark:(line,pink)
 bar:test at:1969 mark:(line,pink)
 bar:test at:1970 mark:(line,pink)
 bar:test at:1971 mark:(line,pink)
 bar:test at:1972 mark:(line,pink)
 bar:test at:1973 mark:(line,pink)
 bar:test at:1974 mark:(line,red)
 bar:test at:1975 mark:(line,pink)
 bar:test at:1976 mark:(line,red)
 bar:test at:1977 mark:(line,red)
 bar:test at:1978 mark:(line,pink)
 bar:test at:1979 mark:(line,magenta)
 at:1979 shift:(10,-3) fontsize:XS text:6 September 1979 3 killed & other damage
 bar:test at:1980 mark:(line,pink)
 bar:test at:1981 mark:(line,pink)
 bar:test at:1983 mark:(line,pink)
 bar:test at:1984 mark:(line,red)
 bar:test at:1985 mark:(line,red)
 bar:test at:1986 mark:(line,pink)
 bar:test at:1987 mark:(line,pink)
 bar:test at:1988 mark:(line,pink)
 at:1989 shift:(10,-2) fontsize:XS text:November 1989 crop damage
 bar:test at:1989 mark:(line,red)
 bar:test at:1990 mark:(line,pink)
 bar:test at:1991 mark:(line,pink)
 bar:test at:1992 mark:(line,pink)
 bar:test at:1993 mark:(line,pink)
 bar:test at:1994 mark:(line,pink)
 bar:test at:1995 mark:(line,pink)
 bar:test at:1996 mark:(line,pink)
 bar:test at:1997 mark:(line,pink)
 bar:test at:1998 mark:(line,pink)
 bar:test at:1999 mark:(line,pink)
 bar:test at:2000 mark:(line,pink)
 bar:test at:2001 mark:(line,pink)
 bar:test at:2002 mark:(line,pink)
 bar:test at:2003 mark:(line,red)
 bar:test at:2004 mark:(line,pink)
 bar:test at:2005 mark:(line,pink)
 bar:test at:2006 mark:(line,pink)
 bar:test at:2007 mark:(line,pink)
 bar:test at:2008 mark:(line,pink)
 bar:test at:2009 mark:(line,pink)
 bar:test at:2010 mark:(line,pink)
 bar:test at:2011 mark:(line,pink)
 bar:test at:2014 mark:(line,pink)
 bar:test at:2015 mark:(line,pink)
 bar:test at:2016 mark:(line,red)
 bar:test at:2019 mark:(line,pink)
 bar:test at:2020 mark:(line,pink)
 bar:test at:2021 mark:(line,pink)
</timeline>

Aso volcano has been active at intervals of approximately 10–20 years with the most active cone in recorded history being Nakadake located in the center of the caldera.[5] It has been active since the sixth century.[6] Eruptions occurred from November 2014 to May 2015, with two major phreatomagmatic eruptions on September 14, 2015, and October 8, 2016.[5] Eruptive activity occurred on 20 October 2021.[3]

Main eruption ages and eruption volume (DRE (dense-rock equivalent) is the equivalent magma eruption volume. The volume of erupted products is much higher):[8]

  • Aso-1: About 266,000 years ago,[9] erupted 32 km3 (7.7 cu mi) DRE.[7]
  • Aso-2: About 141,000 years ago,[9] erupted 32 km3 (7.7 cu mi) DRE.[7]
  • Aso-3: About 130,000 years ago,[10] erupted 96 km3 (23 cu mi) DRE.[7]
  • Aso-4: About 90,000 years ago, erupted 384 km3 (92 cu mi) DRE [7] which was at least VEI 7.
  • Nojiri pumice about 84,000 years ago erupted 1 km3 (0.24 cu mi) DRE.[11]
  • Kusasenrigahama Pumice from Kusasenrigahama at approximately 30,000 years ago[5] erupted 1 km3 (0.24 cu mi) DRE at VEI 5[11]
  • Jigoku spa about 8,050 BCE, Ikph2 tephra[8][1]
  • Janoo before 5,300 BCE Tephta and scora cone[8]
  • Nakadake 5,300 to 12,000 BCE tephra falls[8]
  • near Janoo about 5,300 BCE Akamizu lava flow[8]
  • Near Ikenokubo about 5,300 BCE tuff ring[8]
  • Jigoku Onsen 3,000 to 4,400 BCE tephra, Ikph1 tephra[8][1]
  • Nakadake 3,000 to 4,400 BCE tephra falls[8]
  • Nakadake 4,000 to 3,000 BCE tephra falls[8]
  • Unknown vent near Janoo, 2150 BCE Aso central cone No. 1 pumice, ACP-1 tephra[1]
  • Kishimadake 2,050 BCE >0.02 km3 (0.0048 cu mi) DME VEI 4, KsS tephra[8][1]
  • Nakadake 1,600 to 2,000 BCE tephra falls[8]
  • Ojodake 1,650 BCE >0.02 km3 (0.0048 cu mi) DME VEI 4, OjS tephra[8][1]
  • Komezuka, Kamikomezuka 1,350 BCE tephra 0.05 km3 (0.012 cu mi) DME[8]
  • Unknown Aso 1270 ± 75 BCE[1]
  • Western central cones debris avalanche 100 CE to 400 BCE[8]
  • Nakadake 630 ± 50 BCE tephra falls[8]
  • Nakadake 440 ± 75 CE N2S tephra fall[8][1]
  • See timeline for eruptions in historic written record (KEY-pink if confined to volcano, red tephra fall, magenta human deaths)

Tectonics

There are multiple active faults both under the volcano and adjacent on this area of the Amur Plate. The Okinawa Plate collides with the Amur Plate to the south and the Pacific Plate is subducting under both. The caldera is located where two volcanic lines intersect, being those in the Central Kyushu Rift Valley with volcanoes of Mount Yufu, in Oita Prefecture, through the Kuju volcanoes and Aso Caldera, and on to Mount Unzen and line that runs from Aso Caldera to the Kirishima volcanic group, Aira Caldera, Ata Caldera, and on to the Kikai Caldera.[4] The high resolution Bouguer gravity imaging of Kyushu has confirmed the caldera to be piston rather than funnel shaped, as originally proposed, and related to known active faults and in particular the gravity gradient zone of the Aso Caldera is part of the Oita-Kumamoto Tectonic Line (OKTL) gravity gradient zone and this appears to connect with the Japan Median Tectonic Lines gravity gradient zone, strengthening the evidence that the lines are closely related tectonic features.[12]

Size and other context

Main page: Earth:Mount Aso

In Japan, the caldera forming Lake Kussharo, which measures 26 by 20 km (16 by 12 mi), is larger than Aso caldera leaving it the second largest in Japan. It's not rare to see calderas of this scale; however, to see calderas with an interior stable enough to cultivate land, build highways and lay railroads is quite rare. The caldera contains the city of Aso as well as the town and village of Takamori and Minamiaso.

External links

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 "Asosan |Global Volcanism Program | Smithsonian Institution" (in en). https://volcano.si.edu/volcano.cfm?vn=282110. 
  2. ↑ 2.0 2.1 2.2 "Aso Caldera". https://gbank.gsj.jp/volcano/Quat_Vol/volcano_data/J32.html. 
  3. ↑ 3.0 3.1 "Mount Aso in Kumamoto erupts". nhk.or.jp. https://www3.nhk.or.jp/nhkworld/en/news/20211020_18/. 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 "Aso GeoPark Annex 2：Geological Heritage". http://www.aso-geopark.jp/ggn/pdf/annex2.pdf. 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Huang, YC; Ohkura, T.; Kagiyama, T. (2018). "Shallow volcanic reservoirs and pathways beneath Aso caldera revealed using ambient seismic noise tomography". Earth Planets Space 70 (169): 169. doi:10.1186/s40623-018-0941-2. Bibcode: 2018EP&S...70..169H. 
  6. ↑ 6.0 6.1 6.2 Hata, M.; Matsushima, N.; Takakura, S.; Utsugi, M.; Hashimoto, T.; Uyeshima, M. (2018). "Three-Dimensional Electrical Resistivity Modeling to Elucidate the Crustal Magma Supply System Beneath Aso Caldera, Japan". Journal of Geophysical Research: Solid Earth 123 (8): 6334. doi:10.1029/2018JB015951. Bibcode: 2018JGRB..123.6334H. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JB015951. 
  7. ↑ 7.0 7.1 7.2 7.3 7.4 阿蘇カルデラ. 産総研
  8. ↑ 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 8.11 8.12 8.13 8.14 8.15 8.16 "Asosan: National catalogue of the active volcanoes in Japan". https://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/souran_eng/volcanoes/084_asosan.pdf. 
  9. ↑ 9.0 9.1 阿蘇火砕流について 熊本県高等学校教育研究会 地学部会
  10. ↑ 下山正一、低平地地下における阿蘇3火砕流堆積物(Aso-3)の年代について 佐賀大学低平地防災研究センター編 低平地研究 Vol.10 p.31-38
  11. ↑ 11.0 11.1 Miyabuchi, Yasuo (2009). "A 90,000-year tephrostratigraphic framework of Aso Volcano, Japan". Sedimentary Geology 220 (3–4): 169–189. doi:10.1016/j.sedgeo.2009.04.018. ISSN 0037-0738. Bibcode: 2009SedG..220..169M. https://www.sciencedirect.com/science/article/pii/S0037073809001006. 
  12. ↑ Shichi, R.; Yamamoto, A.; Kudo, T.; Murata, Y.; Nawa, Kazunari; Komazawa, Masao; Nakada, M.; Miyamachi, H. et al. (2005). "A Gravity Database of Southwest Japan: Application to Bouguer Gravity Imaging in Kyushu District, Southwest Japan". A Window on the Future of Geodesy. International Association of Geodesy Symposia. 128. pp. 236–241. doi:10.1007/3-540-27432-4_40. ISBN 3-540-24055-1. https://www.researchgate.net/publication/251134851. 



Retrieved from "https://handwiki.org/wiki/index.php?title=Earth:Aso_Caldera&oldid=3296684"