With the help of modern equipment used in marine geological research, modern processing and interpretation software of sounding data, and GIS software we can acquire accurate and easily presentable data on the quality of the seafloor, the depth of water, and other properties that might have an effect on construction (for example, flows, shipwrecks, previous structures, etc.). Based on the knowledge of the seafloor’s condition it is possible to direct construction to the best possible location and choose the correct construction method.
In disposal site research, we can produce accurate and easily presentable data on the seafloor quality, the depth of water and hard seafloor/rock, and other properties that might have an effect on construction. By using acoustic-seismic methods, we can, for example, assess the size and thickness of underwater soil resources. The sounding data can be used in producing maps and geological cross-sections at the desired scale.
In environmental surveys, the Geological Survey of Finland monitors and studies the present state of the soil (including the seabed) and the man-made changes in it. We are conducting systematic surveying of the seafloor’s heavy metals to acquire information about the state of the seafloor and the distribution of harmful substances in our territorial waters. We have mapped the open sea areas in the Gulf of Finland in the 1990s and completed the mapping of coastal areas in the 2000s. The work continues on other coastal and sea areas on the Finnish Archipelago, the Bothnian Sea and the Bay of Bothnia.
We offer the following services
Surveys concerning harmful substances
Seafloor soil surveys
Surveys related to seafloor construction
Disposal site research
In 2008, GTK conducted a route survey for a planned cable route between Naantali and the Åland Islands. The length of the studied route was 157 kilometres and the width was 300 metres. The survey consisted of 540 kilometres of sounding lines. The sounding was carried out by the Geomari research vessel, which is equipped with sonar, reflection sonar, a side scan sonar and multi beam sonar. By using these tools, GTK was able to determine the accurate depth and the quality of the seafloor. Two separate cable routes were planned for the corridor.
The customer was provided with a report that contained the turning points and distances as tables and the length of the cable along the seafloor. We also provided the customer with accurate water depth and soil type maps and geological cross-sections throughout the route.
Geologist Jyrki Rantataro, jyrki.rantatarogtk.fi