IS18, Qaanaaq, Greenland, Denmark

IS18, Qaanaaq,
Greenland, Denmark

Thumbnail Profile: Greenland

Greenland, the world’s largest island, lies between the Arctic Ocean and the North Atlantic Ocean, northeast of Canada and northwest of Iceland. Devoid of land boundaries, it boasts over 44,000 km of coastline. Greenland possesses the world's second largest ice sheet.

The tiny town of Qaanaaq is about 1,100 km north of the Arctic Circle and is Greenland’s northernmost permanent settlement. Rather uniquely, it counts more huskies than people amongst its resident population. With a population of 640 and a dentist who makes the trip to this town only twice a year, Qaanaaq is also the world’s most northerly palindrome—that is, in this case, a town with a name that reads the same backwards or forwards. Still, that distinction makes it no more geographically accessible! In the middle of nowhere and hours from the next settlement, Qaanaaq can be reached only by helicopter.

Flying north from Thule Air Base at Northmountain, one can witness a rare view of the breathtaking icy and rocky northern coast of Greenland. Also visible from the sky is the vast expanse of the barren Arctic tundra, revealing a magnificent world of icebergs, fiords, and an ice cap that extends eastward to the horizon.


Climate, Topography and Local Customs

Greenland is not green. Rather, its climate is characterized as arctic to subarctic with cool summers and cold winters. The terrain is a mostly flat but gradually sloping icecap that covers all land except for a narrow, mountainous, barren, rocky coast. The lowest point is at sea level while the highest is Gunnbjørn (3,700 m).

Although northern Greenland sunsets tend to linger on for hours, there are brief periods during spring and fall when the difference between night and day is conspicuous. During the winter, the sun disappears out of sight below the horizon for about four months. Still, the brilliant “starshine” and the reflection of moonlight off the snow and ice allows outdoor work to continue in this surreal light.

Local inhabitants can be found hunting narwhale and seals throughout the open water season using traditional methods, including kayaks and harpoons. Appealing to Qaanaaq hunters, the narwhale provides not only meat for the hunter but also whale skins which are rich in vitamins. Polar bears are also hunted during the wintertime.

Station Location

Qaanaaq infrasound station IS18 is the northernmost infrasound station in the International Monitoring System (IMS), covering an area of several thousand kilometres in radius. From this desolate, frigid outpost in northern Greenland, micro-barometers are in operation 24 hours a day to monitor the Earth for evidence of explosions, mainly in the atmosphere, and relay data to the International Data Centre (IDC) in Vienna.

Situated between the town of Qaanaaq and the local airport, IS18 is maintained by the Danish Meteorological Institute (DMI). Station operator Svend Erik Ascanius is based in the town of Qaanaaq and is thus on hand to take immediate action, should any problem occur. This location, chosen by the DMI in collaboration with the CTBTO's Provisional Technical Secretariat (PTS), was deemed more suitable than others for a number of reasons: the village is still inhabited; there is good infrastructure with commercial power available; and wind speeds are comparatively lower than elsewhere. Therefore, the site survey was approved on 20 June 2000.

Station Profile

Infrasound station IS18 consists of an eight-element infrasonic array divided into two sub-arrays equipped with wind noise reduction systems and a Central Processing Facility (CPF).

All IS18 array elements are located, like the village of Qaanaaq, close to the coastline. Each element can be reached with a short walk from the nearby unsealed roads or tracks. Because of the treacherous terrain and harsh climate, a four-wheel drive vehicle is needed at all times to move from Qaanaaq to the nearest point of each array element. The CPF is housed in a building inside Qaanaaq and is easily accessible at all times by the station operator.

Learn more about how infrasound technology works.

Testing, Evaluation and Certification

Authenticated IS18 micropressure and meteorological data were sent to the IMS Laboratory in Vienna, which is used for non-certified stations, between September 2002 and the spring of 2003 via the Global Communication Infrastructure (GCI), when data transmission to the IDC Testbed started. Timely data was received from IS18 over the 154 day test period for 99.4% of the time and the data availability over this period amounted to a total of 99.9%. Both of these figures were well within the required specifications for certification of an IMS infrasound station. Accordingly, IMS infrasound station IS18 was certified on 5 December 2003.

Denmark is also host to another IMS station, auxiliary seismic station AS27 in Sondre Stromfjord, Greenland,  some 1,500 km south of IS18.

Learn more about Denmark and the CTBT.