Knight Inlet

Physical Description

Map and Section

Runoff

There are two main rivers that discharge into Knight Inlet,  the Klinaklini and Franklin, and both enter at the head of the inlet.  The Klinaklini,  the largest river, drains an interior watershed (~ 5780 km²) containing several permanent ice fields.  Trites (1955)  estimated the total mean annual freshwater flow into the inlet to be approximately  410 m³ s^-1 of which  293 m³ s^-1 is from the Klinaklini River.  Runoff to Knight Inlet is highly seasonal, peaking in July because of snow and ice melt from the interior watershed.  The lowest discharge occurs in the winter months because  most of the precipitation is stored as snow in the higher elevations of the watershed.

Deep Water Renewal Process

Knight Inlet has been the chosen location of many oceanographic studies.  In particular, several studies have focused on the dynamics of the energetic stratified flow over the sill of Knight Inlet (Farmer and Smith 1980, Stacey and Pond 1992) and the implications for mixing and estuarine circulation (Freeland and Farmer 1980).

Stacey (1985) briefly describes the deep water renewal cycle in both the inner and outer basins using the observations collected during the 1977 to 1979 intensive sampling period.  For the larger and deeper inner basin, the renewal of the deepest waters (300 m to the bottom) begins in early summer (May-June) and continues through to late fall (October-November).  The relatively high (~3 ml/l) deep water dissolved oxygen levels indicate that renewals are frequent and that a large portion of the deep waters are exchanged.

Care must be taken when interpreting the time series of deep water temperatures and salinities as there are appreciable annual signals: ~ 0.4 °C for temperature and ~ 0.1 PSU for salinity (Pickard 1975). 

Time Series of Deep Water Properties (Inner Basin)

Temperature

• possible warming trend but the time series is noisy because of the large annual signal (~ 0.4 °C) 
• warmest deep water temperatures ever observed occurred in 1999
• coldest temperatures observed in 1979 coincident with cold events also observed in Bute and Jervis Inlets 

Salinity

• no trend is evident
• there is a significant annual signal (~ 0.1 PSU) in the time series

Dissolved Oxygen

• no trend is evident and there is a significant annual signal in the time series
• deep water dissolved oxygen concentrations higher than in most inlets

For comments or questions about this web page contact D. Stucchi at Dario.Stucchi@dfo-mpo.gc.ca