أخدود محيطي

Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches.

الخندق المحيطي Oceanic trench، هو منخفض ضيق وطويل من قاع المحيط، جوانبه شديدة الانحدار، مقوس ويتجه موازيا لحافة قارية عادة.

والخندق عميق جدا وقد يصل عمق الخندق إلى 2 كم تحت سطح قاع المحيط، كما قدي يصل طوله إلى عدة آلاف من الكيلومترات وهو ينشأ نتيجة انحناء لوح محيطي تحت لوح آخر خلال عملية الاندساس subduction. الغلاف الصخري المحيطي يتحرك نحو الأخاديد بمعدل عالمي يبلغ ${\displaystyle{\displaystyle 3\,{\text{km}}^{2}/{\text{yr}}}}$.

 التعريف الجغرافي

Major Pacific trenches (1-10) and fracture zones (11-20): 1. Kermadec 2. تونگا 3. Bougainville 4. ماريانا 5. Izu-Ogasawara 6. اليابان 7. كوريل–كمچاتكا 8. Aleutian 9. Middle America 10. Peru-Chile 11. Mendocino 12. مري 13. مولوكاي 14. Clarion 15. Clipperton 16. Challenger 17. إلتنين 18. Udintsev 19. East Pacific Rise (S-shaped) 20. عرف نازكا

 التعبير المورفولوجي

  The خندق پيرو-تشيله

 العوامل المؤثرة على عمق الخندق

خندق پورتو ريكو

 الخنادق المحيطية الرئيسية

الخندق	المحيط	العمق
Mariana Trench	Pacific Ocean	11,033 m (36,198 ft)
Tonga Trench	Pacific Ocean	10,882 m (35,702 ft)
Kuril–Kamchatka Trench	Pacific Ocean	10,542 m (34,587 ft)
Philippine Trench	Pacific Ocean	10,540 m (34,580 ft)
Kermadec Trench	Pacific Ocean	10,047 m (32,963 ft)
Izu-Bonin Trench (Izu-Ogasawara Trench)	Pacific Ocean	9,780 m (32,090 ft)
Japan Trench	Pacific Ocean	9,000 m (30,000 ft)
Puerto Rico Trench	Atlantic Ocean	8,800 m (28,900 ft)
Peru-Chile Trench or Atacama Trench	Pacific Ocean	8,065 m (26,460 ft)

 الخنادق المحيطية البارزة

الخندق	الموقع
Aleutian Trench	West of ألاسكا
Bougainville Trench	South of New Guinea
Cayman Trench	Western Caribbean Sea
Cedros Trench (inactive)	Pacific coast of Baja California
Hikurangi Trench	East of New Zealand
Izu-Ogasawara Trench	Near Izu and Bonin islands
Japan Trench	Northeast Japan
Kermadec Trench *	Northeast of New Zealand
Kuril-Kamchatka Trench *	Near Kuril islands
Manila Trench	West of Luzon, Philippines
Mariana Trench *	Western Pacific ocean; east of Mariana Islands
Middle America Trench	Eastern Pacific Ocean; off coast of Guatemala, El Salvador, Nicaragua, Costa Rica
New Hebrides Trench	West of Vanuatu (New Hebrides Islands).
Peru-Chile Trench	Eastern Pacific ocean; off coast of Peru & Chile
Philippine Trench *	East of الفلپين
Puerto Rico Trench	Boundary of Caribbean Sea and Atlantic ocean
Puysegur trench	Southwest of New Zealand
Ryukyu Trench	Eastern edge of Japan's Ryukyu Islands
South Sandwich Trench
Sunda Arc and Java Trench
Tonga Trench *	Near Tonga
Yap Trench	Western Pacific ocean; between Palau Islands and Mariana Trench

(*) The 5 deepest trenches in the world

 الخنادق المحيطية القديمة

الخندق	الموقع
Intermontane Trench	Western North America; between Intermontane Islands and North America
Insular Trench	Western North America; between Insular Islands and Intermontane Islands
Farallon Trench	Western North America
Tethyan Trench	South of إيطاليا, Iran, Tibet and Southeast Asia

 انظر أيضا

• Oceanic ridge
• Physical oceanography
• List of landforms
• Trough (geology)
• List of submarine topographical features

 المصادر

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• Hawkins, J. W.; Bloomer, S. H.; Evans, C. A.; Melchior, J. T. (1984). "Evolution of Intra-Oceanic Arc-Trench Systems". Tectonophysics. 102: 175–205. doi:10.1016/0040-1951(84)90013-1.
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