Today’s relief is the result of geological characteristics of the area and the post-Pliocene ingression of sea when the global sea level rose 100 m. The rising of global sea level made changes to the area of Telašćica. Telašćica Bay used to be a dry field divided into three sections – three karst sinkholes with occasional flows of streams. During this period, the relief above sea level was exposed to processes of erosion and corrosion, and abrasion along the coastline. The peaks of mountain chains that stretched in the northwest-southeast direction in several parallel lines are now islands. The most prominent feature of one part of the southwestern coast is a steep slope reaching up to a height of 160 m above sea level at the location of Grpašćak, and stretching down to a depth of 85 m under sea level, presenting one of the greatest steep slopes of the Adriatic. Movements along the fault of Dugi Otok had played a significant role in the formation of the steep slope, and it was further shaped by processes of abrasion because of the coast facing in the direction of the open sea. The entire area of Dugi Otok is located on a seismically active zone with folding, faulting and pulling of the Earth’s crust.
According to a review of landscape units of Croatia specified in the Strategy and Action Plan for the Protection of Biological and Landscape Diversity of the Republic of Croatia (NSAP) (Official Gazette “Narodne novine” 143/08), the area of Nature Park Telašćica belongs to the landscape unit of Zadar-Šibenik maritime zone, and represents the most indented part of the Croatian coast. The vegetation of the islands is in an evergreen area, and the islands are not exposed to the strong bura wind and the salt it carries, so there are no significant differences between the northeastern and southwestern shores. However, there are not any major comprehensive forest zones because the area has since ancient times been used for vineyards, olive groves, livestock and more.
The area of Telašćica belongs to the outer islands, the result of which is significant exposure to influence of the sea, which thus acts on the pressure, temperature and humidity of air. Due to its specific position, the wider area of the Nature Park is exposed to winds, especially the southern wind jugo and the northern wind bura. The influence of the sub-tropical area of high air pressure is evident during summer season, which is usually dry and warm. Certain microclimate features can also be noted in the wider area of the Nature Park. These are primarily conditioned by the influence of the surrounding sea and the hinterland through exposition, relief and altitude.
Moderately rainy climate of the Mediterranean coast is characterized by mild winters and dry summers. This type of climate is also called “olive climate”, and in natural and semi-natural conditions it is connected to the evergreen vegetation of holm oak forests with accompanying degradation and succession stages (maquis, garrigue, grassy meadows, rock gardens, rocks, screes).
Winds from the northern quadrant usually blow in the wider area of the nature Park, and the most frequent one is bura wind, which is especially frequent and strong during the cold season. In contrast, the typical wind in this area during summer months is maestral wind blowing from the northwest. The strongest wind blows from the southern quadrant, especially jugo wind. The entire area has a very small number of days with strong or storm wind. They are most common in winter, and among them, jugo wind (an average of 2.4 Beaufort) and bura wind (Beaufort 1.9) are the most prominent ones. The number of days with wind strength of more than 6 Beaufort is 19 per year, and with wind strength of more than 8 Beaufort 5 days per year.