Submarine Evidence of the Late Weichselian Maximum Extent and the Little Ice Age (LIA) Glacier Limits in the St. Jonsfjorden Region (Svalbard)

Abstract

The paper presents the results of bathymetric mapping of selected tidewater glaciers in the St. Jonsfjorden (Svalbard) between 2004 and 2007. We also used the bathymetric data collected by the Norwegian Hydrographic Service (NHS) as well as the shaded relief images based on them. The most clearly visible traces in submarine marginal zones of the glaciers come from the Little Ice Age (LIA), i.e. the cooling period which in the area of St. Jonsfjorden might have ended no later than about 1900. At the beginning of the 20th century, i.e. during a warm period, the glaciers of St. Jonsfjorden reached their maximums. The youngest traces in the seafloor of the fjord and the bays date from this period, similar to the case of the land marginal zones. In front of the cliff of the Dahl Glacier there is a clearly visible zone of submarine moraines. It finishes exactly along the line of the LIA maximum. The sea-floor relief of the fjord and bays shows traces which we interpret as having been formed during the Late Weichselian (13-10 ka B.P.). At that time, the Dahl Glacier advanced onto the northern part of Hermansenøya; its main stream passed to the north of the island. Simultaneously, the Konow-Osborne Glacier terminated 2 to 4 km from the fjord mouth, leaving about 15 km2 of the fjord ice-free.

Surge dynamics of Aavatsmarkbreen, Svalbard, inferred from the geomorphological record

“…The proper frontal moraines of Aavatsmarkbreen are found at the bottom of the bay (Król et al . ; Sobota et al . ).…”

Geomorphological settings of Polish research areas on Spitsbergen

“…The frontal moraines of the Aavatsmarkbreen and Dahlbreen, terminating in the sea with their several-kilometer-long cliffs, are deposited on the bottom of the bay. They are described in detail by Król et al (2010). The outer push moraines on Elisebreen are described by Klimaszewski (1960) and Olszewski (1977).…”

Contemporary sedimentation in the forefield of Hornbreen,Hornsund

“…Due to the climate warming since the end of the Little Ice Age, the retreat of most glaciers has been observed in Svalbard during 20 th century [1][2][3][4][5][6]. This process is visible especially on the example of tidewater glaciers which terminating in water are more a ected by temperature changes than other glaciers.…”

“…The most prominent mode was in medium silt fraction (≈6.5 phi) and the secondary mode in very ne silt fraction (≈8.5 phi). Exceptions were cores 13 and 14, closest to the ice cli , in which textural group of sandy muds was dominating (sediment names varied from ne silt to very coarse silty very ne sand - Table 2), grain-size distribution varied from unimodal to trimodal and dominating fractions were medium silt (≈6.5 phi), very ne silt (≈8.5 phi) and very ne sand (≈3.5 phi) in di erent combinations (Figures 4,5). All sediments had dark greenish colour and were poorly to extremely poorly sorted, mainly with symmetrical or platykurtic grain-size distribution.…”