Morphology, geology and oceanography of the 
Hinlopen Strait and Trough, Svalbard, Norway 
STEPHANIE PFIRMAN A N D  JOHN D. MILLIMAN 

Pfirman, S. & Milliman, J .  D. 1987: Morphology, geology and oceanography of the Hinlopen Strait and 
Trough, Svalbard, Norway. Polar Research 5 n . s . ,  297-298. 

Stephanie e r m a n ,  Geologisch-Palaontologisches Institut und Museum, Christian-Albrechts Uniuersitat, 
Kiel, F.R.G.; John D .  Milliman, Woo& Hole Oceanographic Institution, Woo& Hole, MA. U.S.A. 

The Hinlopen Strait and Trough (Fig. 1) form a strikingly linear 
NW-SE feature, extending from Svalbard across the shelf and 
onto the Arctic Sea slope. Maximum water depths exceed 
400111, but a number of sills, some presumably structural and 
others sedimentary. divide the strait/trough into a series of 
basins. Acoustically transparent sediment, which locally is 
thicker than 60 m in some basins, is probably late Quaternary 
in age, The upper 1-5m are Holocene, and were probably 
influenced by Atlantic water from the Arctic extension of the 
West Spitsbergen Current. 

Although the Strait appears to be at least partly fault-related, 
the few available seismic data from the Trough show no evidence 
of faulting. The only reasonable alternative - fluvial excavation 
and glacial modification - seems likely if it occurred along a 
zone (or zones) of structural weakness or geological contrast. 
While glaciers may have occupied part or all of the Trough 
during glacial epochs, we see no sign of sediment accumulation 
on the outermost shclf and upper slope, unlike the sediment 
fans that characterize other cross-shelf troughs in the Arctic; 
presumably little or no sediment was discharged onto the Arctic 
slope from the Hinlopen Trough. 



298 S .  Pfirrnan & J .  D .  Milliman 

Fig 1 The Hinlopen Strait and Trough with respect to northern Svalbard Contours in meters