February 19, 2019 - The English Channel

The English Channel

Connecting the Atlantic Ocean and the North Sea, and lying between southern England from France, Belgium and the Netherlands, the English Channel has been a shipping and sailing lane of major importance in Europe throughout historic times. The boat business has been so brisk that the Strait of Dover—the narrowest reach between England and France—has been cited by Guinness World Records as the “world’s busiest shipping lane”, with 500-600 ships passing through the narrow strait each day. The Channel is about 350 mi (560 km) long and 150 mi (240 km) long. It averages 207 feet (63 m) deep, with the deepest point at 571 feet (174 m).

Despite the Channel’s fame and importance, descriptions often fail to evoke grandeur. Perhaps one of the more entertaining descriptions comes from an article by Nigel Calder in the Encyclopedia Britannica’s Britannica Book of the Year: “The English Channel’s waves are not imposing. Surfer’s scorn them. They shrink in height by 50% from the wide Atlantic aperture to the narrow Strait of Dover, where most people cross the currents. But tidal currents, shallow banks, and wave reflections from the cliffs all contribute to a disagreeable choppiness whenever the wind rises above 10 knots. That is why this most important strip of shallow water in the world belongs strictly to sailors”. The Channel does have a wider importance. Tourists, scientists, ferry passengers, swimmers, and many more find the English Channel fascinating. But shipping remains at the center of the business in these waters.

On February 15, 2019, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image centered on the English Channel.

At the time this image was captured, the waters in the Channel were colored in many shades of tan, green and blue. Near the coastlines, as well as in the River Severn (west side of southern England) the muddy-colored tans indicated sediment in the water, most likely from run-off. As sediment sinks, its reflective properties change, and sediment can appear either greenish or blue. Phytoplankton, small plant-like organisms, can also color waters in various shades of greens and blues, especially if the blue has a milky cast. Much of the coloration in the Channel is clearly sediment, but some may also be phytoplankton.

Image Facts
Satellite: Aqua
Date Acquired: 2/15/2019
Resolutions: 1km (226.7 KB), 500m (775.1 KB), 250m (2.6 MB)
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC