This Envisat image captures sea ice in the Sea of Okhotsk off the northeastern coast of Russia's Sakhalin Island (top left) and the northern tip of Japan's Hokkaido Island (bottom left).
Sea ice began forming in the northern area over the Sea of Okhotsk in November 2009. Since then, it extended down to about 30 km off the northern coast of Hokkaido and has likely reached its maximum.
Sakhalin is separated from the east coast of Russia by the narrow Strait of Tartary and from the northern tip of Japan by the Strait of La Pérouse, which appears to be ice-free.
Sitting astride an active seismic zone, Sakhalin is prone to earthquakes that can trigger mudslides. The formal penal colony is covered in ice during the winter months, and its surrounding cool, fertile waters support enormous fisheries. But that's not all; an estimated 45 billion barrels of oil equivalent are believed to lie beneath the icy seas off its shores.
Hokkaido is the northernmost and second largest island of Japan's four main islands. The three islands visible northeast of Hokkaido belong to the Kuril Island chain, which comprises 22 main islands and some 30 smaller islets.
Stretching for 1250 km northwards from Hokkaido to the southern tip of Russia's Kamchatka Peninsula (not visible), the Kuril Islands form a boundary between the Sea of Okhotsk and the Pacific Ocean (bottom right).
This image was acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on 9 March 2010, working in Full Resolution mode to provide a spatial resolution of 300 m.

This Envisat image features the Kuwait islands of Warbah and Bubiyan, located at the head of the Persian Gulf.
What appears to be water across the top and right side of the image (lilac, green and blue) is land. The brighter yellow, aqua and pink colours represent water. Here, the water currents in these channels can be observed thanks to the radar imagery as they flow out into the gulf.
Measuring 30 km wide and 40 km long with an area of 863 sq km, Bubiyan (visible in the bottom right corner) is Kuwait's largest island. It is separated from the Kuwait mainland to the west by the narrow channel Khawr as Sabiyah (visible) and from the mainland in the northeast by the estuary Khawr Abd Allah (visible).
The topography of Bubiyan is flat and low, with the northwestern portion (deeply indented swampland) being partly submerged at high tide. The island has no permanent inhabitants.
Warbah Island (visible as an eye north of Bubiyan between the waterways) is located roughly 100 m east of the Kuwaiti mainland and 1 km south of the Iraqi mainland (across top right) near the mouth of the Shatt al-Arab, formed by the confluence of the Euphrates and the Tigris Rivers. Warbah is roughly 15 km long and 5 km wide with a total area of 37 sq km. Like Bubiyan, it is not inhabited.
The Tigris and Euphrates start near each other in the mountains of Turkey and flow parallel until they meet near the Persian Gulf. The area of the Tigris-Euphrates river system is called Mesopotamia, which translates as “between the rivers”. Many historians consider this as the cradle of civilization.
Kuwait came to international prominence largely because of its enormous oil reserves, which the country reports to be about 104 billion barrels - about 8% of world reserves. The brightly-coloured area in the bottom left contains several oil fields, including the two major fields of Al Rawdatain and Sabriyah. The white lines extending from the oil fields are paved roads.
The image was created by combining three Advanced Synthetic Aperture Radar (ASAR) acquisitions (22 August 2009, 26 September 2009 and 31 October 2009) taken over the same area. The colours in the image result from variations in the surface that occurred between acquisitions.

This Envisat image features a snow-flanked western Norway, located on the Scandinavian Peninsula in northern Europe. Norway, Europe's northernmost country, is famed for its fjords – long narrow arms of the sea that commonly extending far inland. Some of these are visible at the left edge of the land as dark lines between the white and snow-covered land.
During the ice age both ice and rivers carved deep valleys in the mountains. As the climate changed, most of the ice melted, and the valleys were gradually filled with salt water from the coast, giving birth to the fjords. Many fjords are astoundingly deep, reaching hundreds to thousands of metres below sea level.
The Sognefjord (image centre) is Norway's longest and deepest fjord, stretching 205 km inland and reaching a maximum depth of 1308 m below sea level. The average width of the main branch of the fjord is about four-and-a-half km. The only fjord larger than Sognefjord in the world is the Scoresby Sund in Greenland.
South of Sognefjord is the Hardangerfjord, Norway’s second largest and the world’s third largest. It is about 179 km long and has a maximum depth of more than 800 m.
Not all of the ice melted when the climate began to change, so parts of the mountain areas remained covered with ice, creating glaciers. Glaciers cover more than 2600 sq km of Norway’s land area. The largest glacier in Northern Europe, the Jostedalsbreen, is situated north of the Sognefjord’s inland branches. Hardangerjøkulen, the sixth largest glacier in mainland Norway, is located to the east of the most northern inland branch of the Hardangerfjord. It served as the ice planet Hoth in the 1980 movie Star Wars Episode V: The Empire Strikes Back.
With its long coastline and pristine fjords, Norway enjoys good conditions for raising fish stocks. Today, some 800 fish farms dot its coastline, and fish is the third most important export product after oil/gas and metal. In terms of Atlantic salmon, Norway is the leading fish farming country in the world.
North of Hardangerfjord is the city of Bergen, which will host ESA’s Living Planet Symposium, from 28 June – 2 July 2010. Nearly 1000 scientific researchers and data  users are expected to attend the symposium, previously named the Envisat Symposium, where they will present results and compare findings of ongoing research activities using data from ESA’s Envisat, ERS-2, Earth Explorers and Third Party Mission satellites.
This image was acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on 9 February 2010, working in Full Resolution mode to provide a spatial resolution of 300 m.