Johnston Atoll Geography and Climate

Johnston Atoll Geography

The first documentation of Johnston Atoll was made on September 2, 1796, when the American brig Sally ran aground near the islands. Briggs captain Joseph Pierpont published the incident in several American newspapers and then gave an exact position for what he called Johnston and Sand Island. However, he made no claim to the area and it was not until 1807 when Captain Charles J. Johnston on the ship Royal Naval saw the islands that they got their name. During the years that followed, many ships passed by, but they were content to see the atoll and then sail on.

Today, the Johnston Toll counts as an area within the remote islands of the United States. The area has belonged to the United States since March 19, 1858 and is located about 1,400 km west of Hawaii. Johnston Atoll is also known as the Kalama Atoll which is used by Hawaiians. Anyone who wants to visit the islands must have a permit and it is normally only researchers who come here. The atoll has been a sanctuary for birds and has also been used as a place for the navy to refuel. In addition, this area has been used extensively for testing nuclear and biological weapons and for space recovery. Here they have had a secret missile base and as a place to get rid of chemical weapons. All this has led to pollution of the area and because of that, they have had to develop a plan for how to clean and heal the place.

Geography and climate

Johnstonatollen is a group of coral islands that have a total land area of ​​2.8 km². It is thus a very small area which for the most part consists of sand and low vegetation. There are no sources of fresh water here and the islands are uninhabited. Johnstonatollen is today considered a nature reserve. The atoll is located on a coral reef platform and has four different islands, Johnston which is also called Kalama, Sandön, Akau and Hikina. The last two islands are artificial and the first two islands have also been added to enlarge the land area. This has been achieved with coral dredging.

Due to the slope of the atoll, most of the reef on the southeast side has sunk. Even if you do not have a reef that surrounds, there is in the northwestern part of the atoll a shallow lagoon where the depth is between 3-10 meters. The climate is tropical but dry. It is constantly blowing from the northeast and the temperatures do not offer much variation. The vegetation consists mostly of low vegetation and some palm trees.


The Johnston Atoll is one of the most famous atolls in the Pacific Ocean. This is because the effects of all the chemical pollution to which the area has been exposed have been carefully studied. A lot of radioactive material has been buried on the island and to heal the area, a 61 centimeter thick lid has been built over the place where the waste collected from the islands has been buried. This place is carefully marked and the effects of all the pollution to which the atoll has been exposed continue to be investigated.

Johnston Atoll Geography