Glacial geomorphology of Trygghamna, western Svalbard - Integrating terrestrial and submarine archives for a better understanding of past glacial dynamics Nína Aradóttir a, ⁎, Ólafur Ingólfsson a , Riko Noormets b , Ívar Örn Benediktsson a , Daniel Ben-Yehoshua c , Lena Håkansson b , Anders Schomacker d a Institute of Earth Science, University of Iceland, Askja, Sturlugata 7, IS-101 Reykjavík, Iceland b Department of Arctic Geology, University Center in Svalbard (UNIS), P.O. Box 156, N-9171 Longyearbyen, Norway c Svarmi ehf, Árleyni 22, IS-112 Reykjavík, Iceland d Department of Geosciences, UiT The Arctic University of Norway, N-9037 Tromsø, Norway abstract article info Article history: Received 6 May 2019 Received in revised form 11 July 2019 Accepted 12 July 2019 Available online 13 July 2019 Detailed geomorphological mapping was carried out in the terrestrial and submarine forefields of Protektor-, Harriet- and Kjerulfbreen in Trygghamna, western Svalbard, based on high-resolution aerial images and bathy- metric data. The mapping reveals that crevasse-squeeze ridges (CSRs) are only observed on land in the forefield of the surge-type Harriet- and Kjerulfbreen, and recessional moraines are only formed at the sea floor in relation to the retreat of these two glaciers. Different factors affect the preservation potential and formation of landforms between the two environments that could explain the absence of CSRs in the submarine environment and the terrestrial forefield of Protektorbreen. The landform assemblage in Trygghamna does not comply well with existing surge-type glacier landsystem models. We present a conceptual landsystem model for surge-type gla- ciers with combined terrestrial and marine margins, based on the geomorphological archive from Trygghamna. The contrast between the landform assemblages demonstrates how differences in the thermal regime result in different glacier behavior between the warm-based submarine margins and the inactive cold-based terrestrial margin. This study emphasizes the importance of integrating data from both archives to reconstruct past glacier behavior and understand the effect of different glacial dynamics and environments on the preservation potential of sediments and landforms. © 2019 Elsevier B.V. All rights reserved. Keywords: Surge-type glacier Geomorphological mapping Svalbard Glacier thermal regime 1. Introduction The Svalbard archipelago (60,667 km 2 ; Fig. 1A), situated between 74° and 81°N, lies in the main transport path for North Atlantic air masses and ocean currents into the Arctic basin, which explains the rel- atively mild climate and sensitivity to climate change (Hanssen-Bauer et al., 1990; Dickson et al., 2000). Glaciers cover c. 57% of the land area (Nuth et al., 2013) and Svalbard is a hotspot for surging glaciers (e.g., Liestøl, 1969; Lefauconnier and Hagen, 1991; Hagen et al., 1993; Sevestre and Benn, 2015). The number of surge-type glaciers is still un- known with estimates ranging from 13% to 90% of all glaciers in the re- gion (Lefauconnier and Hagen, 1991; Hagen et al., 1993; Jiskoot et al., 1998). Recent works assert that it is difficult to estimate the exact num- ber of Svalbard surge-type glaciers as they are thought to have been more common during the Little Ice Age (LIA) than at present, based on their landform records (Liestøl, 1969, 1988; Hagen et al., 1993; Dowdeswell et al., 1995; Sevestre et al., 2015; Farnsworth et al., 2016; Lovell and Boston, 2017). After the termination of the last major glacier advance marking the peak of the LIA in Svalbard some 100 years ago, glaciers have undergone overall retreat and negative mass balance, exposing extensive areas of formerly glaciated landscape, in both terrestrial and submarine environ- ments (Hagen et al., 1993, 2003; Nuth et al., 2013). The sediment- landform assemblages at the recently deglaciated forefields in front of surge-type glaciers on Svalbard have been of interest for numerous studies of glacial dynamics and paleoclimate reconstructions (e.g., Boulton et al., 1996; Glasser et al., 1998; Evans, 2003; Ottesen and Dowdeswell, 2006; Ottesen et al., 2008; Flink et al., 2015, 2017; Streuff et al., 2018). However, only a few studies have integrated data from terrestrial and submarine forefields for a holistic view of the ice- marginal environment and better understanding of glacial dynamics (Boulton, 1986; Kristensen et al., 2009; Farnsworth et al., 2017; Allaart et al., 2018; Lovell et al., 2018). When reconstructing glacial history and dynamics, surge-type gla- ciers usually pose a challenge because of their cyclic behavior, Geomorphology 344 (2019) 75–89 ⁎ Corresponding author. E-mail address: nia1@hi.is (N. Aradóttir). https://doi.org/10.1016/j.geomorph.2019.07.007 0169-555X/© 2019 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Geomorphology journal homepage: www.elsevier.com/locate/geomorph