equatorial monument

The Equator is an imaginary line on the Earth's surface approximately equidistant from the North Pole and South Pole and it divides the Earth into two Hemisphere - Northern and Southern Hemisphere. In few cities around the world, equatorial markers/monuments have been erected to attract tourists. However, these monuments have some controversy regarding correct location on the exact equator.

The Equatorial Monument in Pontianak, Indonesia erected in Jl. Khatulistiwa and open daily from 7.30 am to 4.30pm. You can contact the place through +62 561 881 643 (voice and fax). This Equatorial Monument was built in 1928 by the International Water Services Expedition Team led by a Dutch geographer, an expert in Dutch Water Services. Based on a 1941 record of V. en V by Opsiter Wiese derived from Bijdragentot de Geographe from Chep Van den Topographeschen dien in Nederlandsch Indie: Den 31 Sten Maart 1928 one international expedition led by a Dutch Geographer come to Pontianak to determine the point of equator line in Pontianak City. It was erected based on astronomical measurement i.e. they did not use satelite or GPS but only based on line and natural objects such as perceived pattern formed by prominent stars within apparent proximity to one another (constellation).

The first monument was made of four poles of Belian or Borneo ironwoods, each with  a diameter of about 0.30m. The frontage poles are about 3.05m high, and the backside poles are about 4.40m high. On the top of the poles, there is an arrow pointed the direction of north to south (latitude 0 degree). It has a flat circle with EVENAAR word on it which means THE EQUATOR (Dutch) on top and 109^oo 20 minutes 00 seconds GMT. 20'0''0 LvGr at the bottow which means the spot is at east longitude 109.

Equator monument has several stages of refinement that starts from the year 1928 which perfected in 1930. It was then revised in 1938 by architect Silaban. In 1990-1991, the government decided to built a duplicate of Equator Monument as well as protective building with the shaped of dome that was launched on 21 September 1991 by the Governor of West Kalimantan, Parjoko Suryo Kusumo. The equator pass through several cities in West Kalimantan province, namely Sekadau, Nanga Dedai as well as several provinces in Indonesia, i.e. West Sumatra, Riau, Central Kalimantan, East Kalimantan, Central Sulawesi, Mollucas, and Papua. It crosses five countries in African continent (Gabon, Zaire, Uganda, Kenya, and Somalia), and four countries in Latin America (Ecuador, Peru, Colombia, and Brazil). In March 2005, there was an effort made by the BPPT (The Agency for the Assessment and Application of Technology) in cooperation with the Municipal Government of Pontianak City to adjust the position of the equator with the monument and came up with a result of approximately 117m differences toward the south of Equator from the original erected monument.

The earth rotates on its axis (rotation) and evolve around the sun (revolution) with a period of one year (365, fourth day). In a year, the sun crosses the Equator twice, from March 21 to 23 when it moves towards the north and from 21 t0 23 September when it moves towards the south. Culmination is an event, where the sun is in a direct line with the Equator. At that day, the sun is in line with the Equator. There will be no shadows of the monument and other things around the monument, which indicates that the monument lies on 0 degree latitude. When the sun is at the center of meridien around March 21 to 23, it is called Vernal Equinox or early spring. And when it happens on September 21 to 23, it is called Autumn Equinox or early fall.