أنواع الثورات البركانية

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Mosaic of some eruptive structures formed during volcanic activity: An eruption column from a Plinian eruption, Pahoehoe lava flow from a Hawaiian eruption, and a lava arc from a Strombolian eruption.

 آليات الثورات البركانية

Diagram showing the scale of VEI correlation with total ejecta volume.

 مؤشر انفجارية البرجان

Volcanic eruptions by VEI index

VEI	Plume height	Eruptive volume *	Eruption type	Frequency **	Example
0	<100 m (330 ft)	1,000 m3 (35,300 cu ft)	Hawaiian	Continuous	Kilauea
1	100–1,000 m (300–3,300 ft)	10,000 m3 (353,000 cu ft)	Hawaiian/Strombolian	Months	Stromboli
2	1–5 km (1–3 mi)	1,000,000 m3 (35,300,000 cu ft) †	Strombolian/Vulcanian	Months	Galeras (1992)
3	3–15 km (2–9 mi)	10,000,000 m3 (353,000,000 cu ft)	Vulcanian	Yearly	Nevado del Ruiz (1985)
4	10–25 km (6–16 mi)	100,000,000 m3 (3.53×109 cu ft)	Vulcanian/Peléan	Few years	Galunggung (1982)
5	>25 km (16 mi)	1 km3 (0.24 cu mi)	Plinian	5–10 years	Mount St. Helens (1980)
6	>25 km (16 mi)	10 km3 (2 cu mi)	Plinian/Ultra Plinian	1,000 years	Krakatoa (1883)
7	>25 km (16 mi)	100 km3 (20 cu mi)	Ultra Plinian	10,000 years	Tambora (1815)
8	>25 km (16 mi)	1,000 km3 (200 cu mi)	Ultra Plinian	100,000 years	Lake Toba (74 ka)
* This is the minimum eruptive volume neccessary for the eruption to be considered within the category. ** Values are a rough estimate. Exceptions occur. † There is a discontinuity between the 2nd and 3rd VEI level; instead of increasing by a magnitude of 10, the value increases by a magnitude of 100 (from 10,000 to 1,000,000).

 ثورات الصخور المنصهرة

Magmatic eruptions produce juvenile clasts during explosive decompression from gas release. They range in intensity from the relatively small lava fountains on Hawaii to catastrophic Ultra Plinian eruption columns more than 30 km (19 mi) high, bigger than the AD 79 eruption that buried Pompeii.

 Hawaiian

المقالة الرئيسية: Hawaiian eruption

Diagram of a Hawaiian eruption. (key: 1. Ash plume 2. Lava fountain 3. Crater 4. Lava lake 5. Fumaroles 6. Lava flow 7. Layers of lava and ash 8. Stratum 9. Sill 10. Magma conduit 11. Magma chamber 12. Dike) Click for larger version.

Ropey pahoehoe lava from Kilauea, Hawaiʻi.

 Strombolian

المقالة الرئيسية: Strombolian eruption

Diagram of a Strombolian eruption. (key: 1. Ash plume 2. Lapilli 3. Volcanic ash rain 4. Lava fountain 5. Volcanic bomb 6. Lava flow 7. Layers of lava and ash 8. Stratum 9. Sill 10. Magma conduit 11. Magma chamber 12. Dike) Click for larger version.

An example of the lava arcs formed during Strombolian activity. This image is of Stromboli itself.

 Vulcanian

المقالة الرئيسية: Vulcanian eruption

Diagram of a Vulcanian eruption. (key: 1. Ash plume 2. Lapilli 3. Lava fountain 4. Volcanic ash rain 5. Volcanic bomb 6. Lava flow 7. Layers of lava and ash 8. Stratum 9. Sill 10. Magma conduit 11. Magma chamber 12. Dike) Click for larger version.

Tavurvur in Papua New Guinea erupting.

 Peléan

المقالة الرئيسية: Peléan eruption

Diagram of Peléan eruption. (key: 1. Ash plume 2. Volcanic ash rain 3. Lava dome 4. Volcanic bomb 5. Pyroclastic flow 6. Layers of lava and ash 7. Stratum 8. Magma conduit 9. Magma chamber 10. Dike) Click for larger version.

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  Pyroclastic flows at Mayon Volcano, Philippines, 1984.

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  The lava spine that developed before the 1902 eruption of Mount Pelée

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  Mount Lamington following the devestating 1951 eruption.

 Plinian

المقالة الرئيسية: Plinian eruption

Diagram of a Plinian eruption. (key: 1. Ash plume 2. Magma conduit 3. Volcanic ash rain 4. Layers of lava and ash 5. Stratum 6. Magma chamber) Click for larger version.

21 April 1990 eruptive column from Redoubt Volcano, as viewed to the west from the Kenai Peninsula.

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 Phreatomagmatic eruptions

المقالة الرئيسية: Phreatomagmatic eruption

 Surtseyan

المقالة الرئيسية: Surtseyan eruption

Diagram of a Surtseyan eruption. (key: 1. Water vapor cloud 2. Compressed ash 3. Crater 4. Water 5. Layers of lava and ash 6. Stratum 7. Magma conduit 8. Magma chamber 9. Dike) Click for larger version.

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  Surtsey, erupting 13 days after breaching the water. A tuff ring surrounds the vent.

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  The fissure formed by the 1886 eruption of Mount Tarawera, an example of a fracture zone eruption.

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  Hole-in-the-Ground, a large maar in Oregon.

 Submarine

المقالة الرئيسية: Submarine eruption

Diagram of a Submarine eruption. (key: 1. Water vapor cloud 2. Water 3. Stratum 4. Lava flow 5. Magma conduit 6. Magma chamber 7. Dike 8. Pillow lava) Click to enlarge.

 Subglacial

المقالة الرئيسية: Subglacial eruption

A diagram of a Subglacial eruption. (key: 1. Water vapor cloud 2. Crater lake 3. Ice 4. Layers of lava and ash 5. Stratum 6. Pillow lava 7. Magma conduit 8. Magma chamber 9. Dike) Click for larger version.

Herðubreið, a tuya in Iceland.

 Phreatic eruptions

المقالة الرئيسية: Phreatic eruption

 انظر أيضا

• قائمة البراكين الثائرة الحالية
• أنواع البراكين
• أكبر الثورات البركانية في العالم

 قراءات إضافية

• Volcanic Ash. University of California Press. 1985. p. 258. ISBN 978-0520052413. Retrieved 5 August 2010. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• "A transient model for explosive and phreatomagmatic eruptions". Journal of Volcanology and Geothermal Research. Volcanic Eruption Mechanisms - Insights from intercomparison of models of conduit processes. 143 (1–3): 133–151. May 2005. doi:10.1016/j.jvolgeores.2004.09.014. Retrieved 5 August 2010. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Pyle, D. M. (January 1989). "The thickness, volume and grainsize of tephra fall deposits". Bulletin of Volcanology. 51 (1): 1–15. doi:10.1007/BF01086757.
• "Quantitative shape measurements of distal volcanic ash" (PDF). Journal of Geophysical Research. 108 (B10). 28 October 2003. doi:10.1029/2001JB000818. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• William Henry Mathews (September 1947). ""Tuyas," flat-topped volcanoes in northern British Columbia". American Journal of Science. 245: 560–570.. This is the original landmark paper by William Henry Mathews that first described tuyas and subglacial eruptions.

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 وصلات خارجية

• USGS Hawaiian Volcano Observatory (HVO) homepage. USGS.
• Distinguishing eruptive types.
• How Volcanoes Work. San Diego State University.