Oceanography

The continental shelf around Iceland is generally fairly wide except south of the country. In some areas it extends to over 150 km and in other locations it is cut by many subsea canyons. Beyond the shelf, the seafloor falls away from 200 to 400 m on the shelf to a depth of over 1000 m, although subsea ridges extend to the north (Jan Mayen and Kolbeinsey Ridges), east (Iceland-Faroe ridge), west (Iceland-Greenland ridge) and southwest (Reykjanes Ridge). Almost the entire shelf around Iceland is covered by the EEZ.

The three major current systems that influence Icelandic waters are the warm and saline Irminger current, an offshoot from the Gulf Stream, flowing from the south, the very cold and less saline East Greenland current from the north-west, and the intermediate East Icelandic current from the north-east. The East Greenland current flows directly from the Arctic, but the East Icelandic current is made up from the merging of cold Arctic waters and the warmer Atlantic waters north-east of Iceland. The Irminger current flows around the western, north-western and northern part of Iceland, but is mixed on the way with the colder currents.

The climate conditions in Icelandic waters during the 20th century can be roughly divided into 4 periods. From the beginning of the century until around 1925, the climate was generally cold. After that came a warmer period which lasted until 1964 and a cold period again until 1971. The beginning of this period is marked by the collapse of herring stock around Iceland. After this, the climate has been intermediate but fluctuating. A warming trend appears to have started again near the end of the 20th century.

Steingrímur Jónsson, The Marine Research Insitute/University of Akureyri