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Russia Earthquake & Tsunami

30 Jul 2025 GS 1 Geography
Russia Earthquake & Tsunami Click to view full image

Location:

  • Severo-Kurilsk, Paramushir Island

  • Kuril Islands, Russia

  • Near Kamchatka Peninsula, located in the Pacific Ring of Fire

           

Event :

  • Magnitude: 8.8 on the Richter scale

  • Type: Subduction zone earthquake

  • Impact:

    • Triggered tsunami waves

    • Affected regions:

      • Russia’s Far East

      • Japan

      • Hawaii

      • US West Coast (California, Oregon)

  • Reports of coastal inundation in Severo-Kurilsk

Geophysical Significance:

  • Ring of Fire:

    • Highly seismically active region around the Pacific Ocean

    • Includes volcanic arcs and oceanic trenches

  • Tsunami Trigger:

    • Vertical displacement of sea floor during the quake

    • Tsunami waves radiate across Pacific Ocean basin

Tectonic Setting of the Region (Kuril to Taiwan)

Major Tectonic Plates Involved

  1. Pacific Plate – Moving westward and subducting beneath Japan.

  2. Philippine Sea Plate – Moving northwestward, also subducting beneath Japan.

  3. Eurasian Plate – Stable continental plate to the west.

  4. Okhotsk Plate (part of North American Plate) – Sometimes considered a microplate involved in North Japan dynamics.

Subduction Zones and Trenches

These are deep-sea trenches formed due to one plate sliding beneath another:

  1. Kuril Trench – Pacific Plate subducting under the Kuril Arc.

  2. Japan Trench – Pacific Plate subducting beneath Northeast Japan Arc.

  3. Izu–Bonin Trench – Pacific Plate subducting under the Izu–Bonin Arc.

  4. Ryukyu Trench – Philippine Sea Plate subducting under the Ryukyu Arc.

  5. Okinawa Trough – Back-arc spreading zone behind the Ryukyu Arc.

Volcanic Arcs and Arc Collision Zones

  1. Kuril Arc – Linked to the Kuril Trench, seismically active.

  2. Northeast Japan Arc – Over Japan Trench, includes Tohoku region.

  3. Southwest Japan Arc – In C. Honshu and Kyushu, facing the Nankai Trough (not shown).

  4. Ryukyu Arc – Volcanic arc over the Ryukyu Trench.

  5. Izu–Bonin Arc – Important oceanic island arc south of Honshu.

  6. Hidaka Collision Zone – Where the Kuril Arc collides with Japan (Hokkaido region).

Key Interactions and Features

  • Arc-Arc Collision: The Kuril Arc and Northeast Japan Arc are colliding near Hokkaido, forming the Hidaka Mountains.

  • Triple Junction near Honshu: Intersection of Pacific, Philippine Sea, and Eurasian Plates.

  • High Seismic Risk Zones: All subduction trenches are major earthquake-generating zones. The 2011 Tohoku earthquake occurred along the Japan Trench.



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