Coastal geoscience field work near Iqaluit, Nunavut, 2009-2011

Abstract

This report describes data collected during five field trips to Koojesse Inlet, Nunavut, between 2009 and 2011. These trips have expedition numbers 2009306, 2010307, 2011303, and 2011307 (includes 2 trips). Koojesse Inlet is in the northwestern end of Frobisher Bay on Baffin Island. Data were collected primarily on foot within the intertidal, but there are some boat-based datasets associated with expedition 2011307. Data collected include: RTK-GPS transects, sidescan sonar lines, single beam sonar lines, tide and wave recorder deployments, current profiler deployments, surface and grab sediment samples, underwater drop camera lines, and shallow sub-bottom profile lines. Results show a complex intertidal zone characterized by a higher slope beachface and ank face at the edge of the low-slope tidal at terrace, with varying concentrations of boulders. Sediment is a mixture of relict glaciomarine overlain by a shallow reworked sand/mud surficial layer. Sediment in the nearshore varies from fine silts to cobble/gravel deposits in the more exposed areas. This study was unable to resolve significant amounts of erosion on the tidal at surface, but the geomorphological evidence is irrefutably indicative of an erosional landform.

Exposure to Coastal Hazards in a Rapidly Expanding Northern Urban Centre, Iqaluit, Nunavut

“…It coincided with a moderate storm with minimum sea level air pressure of 98.6 hPa and easterly winds above 35 km/h, sustained for four hours. In an earlier preliminary report (Hatcher et al, 2011), we erroneously documented a 1.37 m storm surge associated with this event. However, subsequent more rigorous analysis of the tidal data and predictions uncovered timing errors, and the actual offset averaged over that tidal cycle was 0.2 m. This suggests that upper Frobisher Bay, inside the band of islands in the mid-bay region, is somewhat protected from storm surges, although decimetrescale wind setup, barometric, and ocean dynamic effects occur, as well as wave setup amounting to less than 10% of deepwater wave height (Dean et al, 2005).…”

“…Recent rapid population growth complicates this effort, as the existing infrastructure deficit creates an added burden for investment in solutions. In this context, previous work has identified hazards at the coast, including sea level change, extreme water levels, and changing sea ice patterns, as a topic requiring further investigation to better define the associated exposure and risk (Shirley, 2005;Nielsen, 2007; City of Iqaluit, 2010;Hatcher et al, 2011).…”