Stations

The African Sea Level Network.

A survey of the status of the African Sea level network was undertaken in 2005 in order to select potential locations for installation of new tide gauges, and also to assess which existing equipment required upgrade. This was done on the basis of a questionnaire sent to national contacts, as well as reports from previous surveys (GLOSS, GOOS Africa). The survey revealed the existence of at least 40 operational stations spread unevenly along the African coastline and island states. In the Indian several stations installed by the University of Hawaii within the framework of the TOGA project are still functioning. South Africa has an extensive network of gauges along its coastline. Other countries that have established national tide gauge networks include Morocco, and Mozambique. Large stretches of coastline did not have any operational gauges. There were gauges at eight (8) locations which were not working. Only two stations in the entire network met the specifications for tsunami early warning system (Rodrigues and Port Louis, both in Mauritius). The most common model of installed tide gauge was the OTT float gauge, followed by Handar encorders at stations that are installed and maintained by the University of Hawaii Sea Level Centre in the Indian Ocean.

Timelines for installation of GLOSS stations along Africa coastline

  Category 1: Operational

  Category 2: 2007

  Category 3: 2006

  Category 4: Unknown

Assessment of sites for installation of new tide gauges.

In preparation for the installation of ODINAFRICA tide gauges, technical visits were undertaken to inspect the sites proposed for the installations in:

• Mauritania, Cameroon, and Congo (by David Dixon in October 2005);

• Madagascar and Comoros (by Fredric Simon in May 2006);

• Egypt (by David Dixon in November 2006),

• Senegal (by Angora Aman in December 2006)

• Morocco (by David Dixon in February 2007). 

Reports of other assessment missions undertaken earlier are also available:

• Egypt, Sudan and Djibouti (by Cherif Samari in 2004)

• Egypt and Sudan (by Alan Browell in 1987). 

Installation of New tide gauges by ODINAFRICA. 

New tide gauges have now been installed at the following locations by ODINAFRICA: 

• Nouakchott, Mauritania (December 2006)

• Takoradi, Ghana (December 2006)

• Djibouti, Djibouti (February 2007)

• Pointe Noire, Congo (April 2007, report to be available soon).

The ODINAFRICA Sea Level station configuration consists of (i) A Kalesto radar gauge; (ii) two pressure sensors; (iii) a Logosens-2 datalogger; and (iv) an OTT HDR DCP satellite transmitter for the Meteosat.

Installations by other partners. 

In addition the following sea level stations have been upgraded within the framework of the Indian Ocean Tsunami Early Warning and Mitigation System: Mombasa and Lamu (Kenya), Zanzibar (Tanzania), Pointe La rue (Seychelles), Rodrigues and Port Louis (Mauritius).  

New stations have been installed at Inhambane and Pemba (Mozambique) within the framework of the GLOSS programme. 

ODINAFRICA has established collaboration with the Permanent Service for Mean Sea Level, Indian Ocean Tsunami Warning and Mitigation System, SHOM and Benguela Current LME project to ensure that there is a more comprehensive network of evenly spaced sea level stations, providing data near real-time, and addressing the key oceanographic phenomena along the African coastline. Other stations that will be installed/upgraded within the framework of this collaboration include: 

ODINAFRICA:  Limbe (Cameroon), Alexandria (Egypt), Nosy Be (Madagascar), Casablanca (Morocco), Dakar (Senegal), and Cap Bon (Tunisia).

IOTWS/GLOSS: GLOSS will also install satellite transmitters at Simonstown, Port Elizabeth and Durban (South Africa) 

BCLME (5): plans to install gauges at Lamberts Bay (South Africa), Luderitz and Walvis Bay (Namibia), and Namibe and Luanda (Angola).

SHOM –France (3): plans to instal gauges at Point des Galets-La Reunion, Dzaoudzi- Mayottee (France), and Tamatave (Madagascar). 

NATIONAL ORGANISATIONS (4): Shimoni, Malindi, and Lamu (Kenya), Lagos (Nigeria).

The development of the GLOSS Africa and it's website is supported by ODINAFRICA