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Minor plate · oceanic and continental crust

Okhotsk Plate

Also called the Sea of Okhotsk Plate

The Okhotsk Plate is a minor plate in the northwest Pacific that carries Kamchatka, the Kuril Islands, Hokkaido and northeastern Honshu. The Pacific Plate dives beneath its eastern edge, producing some of the largest earthquakes ever recorded, including the 2011 Tohoku earthquake.

Area
3.04 million km²
Share of Earth
0.6%
Size rank
15 of 52
Avg boundary speed
3.3 cm/yr
Map showing the location of the Okhotsk Plate and its neighbors Okhotsk Amur Open on interactive map

Boundaries of the Okhotsk Plate

9,459 km of boundary in total: 70% convergent, 12% divergent, 18% transform. Speeds are relative motion between the two plates, from the PB2002 model.

Neighboring plate Boundary type Main features Shared length Relative speed
Pacific Plate Convergent Subduction zone 3,016 km 7.9-9.3 cm/yr
North American Plate Transform Continental transform fault, Subduction zone 2,432 km 0.3-0.5 cm/yr
Amur Plate Convergent Continental collision zone, Oceanic convergent boundary 2,304 km 0.7-0.9 cm/yr
Eurasian Plate Divergent Continental rift, Continental transform fault 1,395 km 0.4-0.5 cm/yr
Philippine Sea Plate Convergent Oceanic convergent boundary, Continental collision zone 312 km 3.4-3.6 cm/yr

Where it is and what it carries

The Okhotsk Plate covers about 3.0 million square kilometers, or 0.6% of Earth’s surface. Its center is the Sea of Okhotsk, and its rim carries the Kamchatka Peninsula, the Kuril Islands, part of Sakhalin, Hokkaido and northeastern Honshu. In the dataset, 54.6% of Japan and 3.7% of Russia lie on the plate. The crust is mixed: continental and island-arc crust on land, and thinner, stretched crust under parts of the Sea of Okhotsk.

Many textbooks fold this region into the North American Plate. The PB2002 model, like several GPS-based studies, separates it. The 2,432 km boundary between them is mostly continental transform and moves at only about 0.3-0.5 cm/yr, which is why the split is still debated.

The trenches on its eastern edge

The plate’s most active boundary is with the Pacific Plate. Along 3,016 km of subduction zone, the Pacific seafloor sinks westward beneath the plate at a relative speed of about 7.9-9.3 cm/yr. From north to south this boundary is the Kuril-Kamchatka Trench, running along Kamchatka and the Kuril Islands, and the Japan Trench off northeastern Honshu.

The Pacific crust entering these trenches is old, cold and dense. It sinks steeply into the mantle, and its downward pull and fast convergence load the plate boundary with strain that is released in great earthquakes.

Western and southern edges

To the west, the plate meets the Amur Plate along 2,304 km of convergent boundary through Sakhalin and the eastern margin of the Sea of Japan. The two plates squeeze together slowly, at about 0.7-0.9 cm/yr. Farther north, a 1,395 km boundary with the Eurasian Plate is mostly continental rift moving at about 0.4-0.5 cm/yr.

In the south, near Tokyo, the plate touches the Philippine Sea Plate along 312 km at about 3.4-3.6 cm/yr. This short boundary includes the Sagami Trough, the source of the 1923 Great Kanto earthquake, and the collision zone where the Izu Peninsula pushes into Honshu.

Great earthquakes

The dataset lists 443 earthquakes of magnitude 6.5 or larger on the plate since 1900, and 13 of them reached magnitude 8 or more. That is a remarkable count for a plate this size. The largest was the 2011 Tohoku earthquake (M9.1) on the Japan Trench. Its tsunami flooded the Pacific coast of northeastern Japan and caused the Fukushima Daiichi nuclear accident.

Kamchatka has produced two of the largest earthquakes on record. The 1952 Kamchatka earthquake (M9.0) sent a tsunami across the Pacific, and the 2025 Kamchatka Peninsula earthquake (M8.8) struck nearby and also triggered Pacific-wide tsunami warnings. The Kuril Islands add the 1963 (M8.5), 1958 (M8.3), 1994 Shikotan (M8.3) and 2006 (M8.3) earthquakes, and Kamchatka the 1923 earthquake (M8.4).

Volcanoes

The plate holds 154 volcanoes in the dataset, one of the highest counts of any plate. Kamchatka has the densest cluster. Klyuchevskaya Sopka is the tallest active volcano in Eurasia, Bezymianny blew out its side in a huge lateral blast in 1956, and Sheveluch and Karymsky erupt often. The Kuril Islands form a chain of volcanic islands, including Alaid, Ebeko and Chikurachki, and in Hokkaido the Akan caldera sits at the southwestern end of the Kuril arc.

Countries on the Okhotsk Plate

Share of each country's land area that lies on this plate.

Largest earthquakes on the Okhotsk Plate

443 earthquakes of magnitude 6.5 or more since 1900 had their epicenter on this plate, 13 of them magnitude 8 or larger. Data: USGS.

EarthquakeMagnitudeYearDepth
Great Tohoku Earthquake, Japan · Japan M9.1 2011 29 km
89 km ESE of Petropavlovsk-Kamchatsky, Russia · Russia M9.0 1952 22 km
Kamchatka Peninsula, Russia Earthquake · Russia M8.8 2025 35 km
Kuril Islands Earthquake · Russia M8.5 1963 35 km
Kamchatka, Russia Earthquake · Russia M8.4 1923 15 km
Kuril Islands Earthquake · Russia M8.3 1958 35 km
48 km E of Shikotan, Russia · Russia M8.3 1994 14 km
Kuril Islands Earthquake · Russia M8.3 2006 10 km

Volcanoes on the Okhotsk Plate

The Smithsonian Global Volcanism Program lists 154 Holocene volcanoes on this plate. The most recently active:

See all volcanoes on the live map

Frequently asked questions

Is Japan on the Okhotsk Plate or the North American Plate?

Many textbooks say northern Japan sits on the North American Plate. The PB2002 model used on this site places Hokkaido and northeastern Honshu on the separate Okhotsk Plate, and southwest Japan on the Amur Plate. Both views describe the same geology; they differ on whether the Okhotsk block moves independently of North America.

Which plate caused the 2011 Tohoku earthquake?

The M9.1 Tohoku earthquake struck on the Japan Trench, where the Pacific Plate subducts beneath northeastern Honshu. In the PB2002 model the overriding plate is the Okhotsk Plate. The rupture let the Okhotsk side spring upward and eastward, which lifted the seafloor and launched the tsunami.

Is the Okhotsk Plate part of the North American Plate?

That is still debated. Some GPS and earthquake studies show the Okhotsk block moving slightly differently from North America, so models such as PB2002 treat it as its own plate. The motion between them is very small, only about 0.3-0.5 cm/yr along their shared boundary in PB2002, so other models merge the two.

Why does Kamchatka have so many volcanoes?

Kamchatka sits above the Kuril-Kamchatka Trench, where the Pacific Plate sinks fast and steadily into the mantle. Water released from the sinking slab helps melt the mantle above it, and the magma rises to feed a chain of active volcanoes such as Klyuchevskaya Sopka, Sheveluch, Bezymianny and Karymsky.

How big is the Okhotsk Plate?

The Okhotsk Plate covers about 3.04 million km² (1.17 million sq mi), roughly 0.6% of Earth's surface. That makes it the 15th largest of the 52 plates in the PB2002 model.

How fast does the Okhotsk Plate move?

Measured against its neighbors, the Okhotsk Plate moves at an average of 3.3 cm/yr (1.3 in/yr) along its boundaries. The fastest motion is against the Pacific Plate, where relative speeds reach 9.3 cm/yr on a convergent boundary.

What countries are on the Okhotsk Plate?

Countries mostly on the Okhotsk Plate: Japan. Countries partly on it: Russia. Shares are measured by land area using Natural Earth outlines.

What plates border the Okhotsk Plate?

The Okhotsk Plate shares boundaries with 5 plates: the Pacific Plate (convergent), the North American Plate (transform), the Amur Plate (convergent), the Eurasian Plate (divergent), the Philippine Sea Plate (convergent).

All 52 tectonic plates