Through the Velebit mountains

The Velebit mountains are 145km long and 10 to 30km wide. They are the longest part of the Dinaric mountain system between the Alps in the north and the Albanian Alps in the south. It is added to the Adriatic coastal belt of the Dinaric mountain folds, which are characterized by steeply rising, low-water coastal karst areas. The highest peak is Vaganski Vrh with 1757 m.

Since the Devonian (416 to 359.2 MBP), particularly in the Jurassic (199.6 to 145.5 MBP) and the Cretaceous Period (145.5 to 65.5 MBP), up to modern times were carbonate and dolomite sediments deposited in the lowering basin, which now reach a thickness of about 4km. The collision of African-Arab with the Eurasian plate since the Oligocene (33.9 to 23.03 MBP) folds the mountains (like the Alps). During the Quaternary ice ages, the Velebit mountain range was largely free of ice, so that their influence was low on the geological processes.

Like the entire Dinaric mountain system, the Velebit mountain range consists mainly of limestone. Limestone is very porous and cracked the one hand, but also very hard and resistant to erosion. Water flows through the pores and cracks and chemically decomposes the limestone. The water, together with the carbon dioxide in air or sulfur compounds of the soil acids dissolve the calcium carbonate of the limestone. In this way, the enlarged pores and cracks become underground passageways. These events are the basis of karstification, which here in the outer Dinarides occurs particularly clear in appearance.

The Velebit mountain range is the source of up to Italy acting strong gusty, cold and dry Bora (Bura) winds. They form when cold continental air from the east reach the Adriatic Sea at the western slopes of the Velebit mountain range. The winds last in summer a few hours, in winter up to 14 days. The gusts reach particularly in transitional periods of spring and autumn speeds of more than 200km/h. For this reason, the A1 motorway between the Maslenica bridge and the Sveti Rok Tunnel is closed occasionally to prevent accidents. Here are unique in the world wind barriers tested, intended to permit traffic even in stronger winds.

The eastern slopes of the Velebit Mountains are largely forested. The coastal side, however, is of very sparse vegetation. A characteristic feature of the landscape on the west side are bright limestone rocks , because the lack of bare soil. Due to the dryness of the Bora wind this side has very little water. Thus, on the basis of vegetation particularly clear, that the mountains separate two climate zones from each other, the mountain climate in the interior to the east and the Mediterranean climate on the coast in the west. The entire Velebit mountain is now a national park and protected area.

The Sveti Rok Tunnel connects on a length of 5.7 km the east and west side of the Velebit mountain range between the villages of Sveti Rok in the east and the west Maslenica. The construction was begun in 1993 and it was even promoted in the war. The first tunnel was opened to traffic in 2003, when both tubes were finished, the second tube in 2009. During the building large cave systems were crossed, which made the construction very complicated. After the Mala Kapela Tunnel Sveti Rok Tunnel is the second longest road tunnel in Croatia. The safety of both tunnels are among the most modern in Europe, so they are always rated very well in the relevant tests.

The location at the picnic area at Sveti Rok Tunnel offers a very nice overview of the bare peaks of the Velebit mountains, over its western flank and the flat coastal land with the Strait of Maslenica, to the islands. The tables and benches of the picnic area invite to a small break of the trip, and there may also the following questions be answered: