Thomas Sinclair James

Thomas Sinclair James
Natural Resources Canada | NRCan · Geological Survey of Canada

Ph.D.

About

145
Publications
29,961
Reads
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5,008
Citations
Citations since 2016
16 Research Items
1781 Citations
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Additional affiliations
July 2006 - present
University of Victoria
Position
  • Professor (Associate)

Publications

Publications (145)
Technical Report
Full-text available
The Canadian Geodetic Survey of Natural Resources Canada maintains the Canadian Spatial Reference System (CSRS), the fundamental standard for the measurement of latitude, longitude, and elevation in Canada. On a dynamic planet these coordinates are constantly changing. NRCan uses a network of GPS sensors to monitor crustal motion in Canada, and pro...
Chapter
Full-text available
This chapter describes physical and chemical changes in the oceans surrounding Canada on decadal and longer time scales, and discusses these changes in the context of anthropogenic climate change and natural climate variability.
Article
Full-text available
A refined relative sea level (RSL) history spanning the past 14,300 calendar years is described for the Quadra Island area in the northern Strait of Georgia on the Pacific coast of Canada. Here marine shorelines dating to the time of earliest post-glacial emergence are at least 197 m above present-day sea-level at 14,300 years ago. RSL fell rapidly...
Article
The ocean load in glacial isostatic adjustment (GIA) modelling is represented by the so-called sea-level equation (SLE). The SLE describes the mass redistribution of water between ice sheets and oceans on a deforming Earth. Despite various teams independently investigating GIA, there has been no systematic intercomparison amongst the numerical solv...
Article
Full-text available
EON-ROSE (Earth-System Observing Network-Réseau d’Observation du Système terrestrE) is a new initiative for a pan-Canadian research collaboration to holistically examine Earth systems from the ionosphere into the core. The Canadian Cordillera Array (CC Array) is the pilot phase, and will extend across the Cordillera from the Beaufort Sea to the U.S...
Conference Paper
Full-text available
An updated national-scale crustal velocity model has been developed for Canada as part of the realization of its NAD83(CSRS) 3-dimensional geodetic reference frame. The velocity model, expressed as an interpolation grid, is used to propagate coordinates to different reference epochs in use throughout Canada, and to support scientific studies such a...
Article
Full-text available
New precise network solutions for continuous GPS (cGPS) stations distributed in eastern Ontario and western Québec provide constraints on the regional three-dimensional crustal velocity field. Five years of continuous observations at fourteen cGPS sites were analyzed using Bernese GPS processing software. Several different sub-networks were chosen...
Poster
Full-text available
A national-scale crustal velocity model has been developed for Canada as part of the current realization of NAD83(CSRS). It is used to propagate coordinates to different reference epochs, and to support scientific studies such as natural hazards related to earthquakes and sea level rise. The current velocity model is based solely on continuous and...
Chapter
Full-text available
Full report available for free download from: http://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/earthsciences/pdf/assess/2016/Coastal_Assessment_FullReport.pdf
Article
The thickness and equivalent global sea level contribution of an improved model of the central and northern Laurentide Ice Sheet is constrained by 24 relative sea level histories and 18 present-day GPS-measured vertical land motion rates. The final model, termed Laur16, is derived from the ICE-5G model by holding the timing history constant and ite...
Article
Full-text available
Sea-level allowances at 22 tide-gauge sites along the east coast of Canada are determined based on projections of regional sea-level rise for the Representative Concentration Pathway 8.5 (RCP8.5) from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5) and on the statistics of historical tides and storm surges (s...
Article
Full-text available
On 28 October 2012, an Mw 7.8 earthquake occurred off the west coast of Haida Gwaii, British Columbia. Although past large events at this margin reflect strike-slip motion between the Pacific and North American plates (e.g., 1949 Ms 8.1), this earthquake involved low-angle thrust faulting with a slip direction almost perpendicular to the margin, a...
Article
Full-text available
The 27 October 2012 Mw 7.8 Haida Gwaii thrust earthquake and the 5 January 2013 Mw 7.5 Craig strike‐slip earthquake are the focus of this special issue. They occurred along the transform boundary between the Pacific and North American plates (Fig. 1). The most identifiable feature of the plate boundary, the strike‐slip Queen Charlotte fault, might...
Article
Full-text available
This paper documents the methodology of computing sea-level rise allowances for Atlantic Canada in the 21st century under conditions of uncertain sea-level rise. The sea-level rise allowances are defined as the amount by which an asset needs to be raised in order to maintain the same likelihood of future flooding events as that site has experienced...
Article
Full-text available
Relative sea-level projections are provided for 59 locations in Canada and 10 in the adjacent mainland United States (New England and Washington State) through the 21st century, relative to 1986-2005. The projections are based on the Representative Concentration Pathway (RCP) scenarios of the Fifth Assessment Report of the Intergovernmental Panel o...
Conference Paper
Full-text available
The safety of navigation and the ability to develop safe ports and coastal infrastructure in Arctic harbours depends on the availability of detailed information on seabed bathymetry, sediments and their dynamics as well as on coastal geomorphology and processes. Arctic harbours generally experience issues of ice cover, nearshore ice impacts, waves,...
Article
Thirty-six new and previously published radiocarbon dates constrain the relative sea-level history of Arviat on the west coast of Hudson Bay. As a result of glacial isostatic adjustment (GIA) following deglaciation, sea level fell rapidly from a high-stand of nearly 170 m elevation just after 8000 cal yr BP to 60 m elevation by the mid Holocene (~...
Chapter
Full-text available
This paper summarizes observations of surficial geology and landscape hazards relevant to infrastructure stability and community sustainability in Arviat, Nunavut. It is based on a site visit and rapid reconnaissance survey in July 2009 in support of climate-change adaptation planning. The scientific work focused on surficial deposits, permafrost a...
Article
[1] Gravity Recovery and Climate Experiment (GRACE) satellite-derived total water storage can be obscured by glacial isostatic adjustment. In order to solve this problem for the Nelson River drainage basin in Canada, a gravity rate map from 110 months (June 2002 to October 2011) of GRACE gravity data was corrected for glacial isostatic adjustment u...
Article
Full-text available
Small tropical islands are widely recognized as having high exposure and vulnerability to climate change and other natural hazards. Ocean warming and acidification, changing storm patterns and intensity, and accelerated sea-level rise pose challenges that compound the intrinsic vulnerability of small, remote, island communities. Sustainable develop...
Article
Full-text available
[1] Antarctic volume changes during the past 21 thousand years are smaller than previously thought and here we construct an ice sheet history that drives a forward model prediction of glacial isostatic adjustment (GIA) gravity signal. The new model, in turn, should give predictions constrained with recent uplift data. The impact of the GIA signal o...
Article
At 8:04 P.M. Pacific daylight time (PDT) on 27 October 2012 (03:04 universal time (UT), 28 October), Canada's second largest instrumentally recorded earthquake rocked Haida Gwaii (formerly Queen Charlotte Islands) and the mainland coast of British Columbia. The M 7.7 event off the west coast of Moresby Island caused a tsunami with local runup of mo...
Article
Understanding the response of the Earth to the waxing and waning ice sheets is crucial in various contexts, ranging from the interpretation of modern satellite geodetic measurements to the projections of future sea level trends in response to climate change. All the processes accompanying Glacial Isostatic Adjustment (GIA) can be described solving...
Article
Full-text available
We present Global Positioning System (GPS) position time series from eastern North America that constrain the pattern and magnitude of regional crustal deformation. Initial analysis delineates consistent uplift patterns, as expected from glacial isostatic adjustment (GIA) predictions, but the associated horizontal deformation is not definitive, in...
Article
Full-text available
Groundwater is a primary hydrological reservoir of the Great Lakes Water Basin (GLB), which is an important region to both Canada and US in terms of culture, society and economy. Due to insufficient observations, there is a knowledge gap about groundwater storage variation and its interaction with the Great Lakes. The objective of this study is to...
Conference Paper
The study of the process of Glacial Isostatic Adjustment (GIA) and of the consequent sea level variations is gaining an increasingly important role within the geophysical community. Understanding the response of the Earth to the waxing and waning ice sheets is crucial in various contexts, ranging from the interpretation of modern satellite geodetic...
Article
The former Laurentide ice sheet was centred over Hudson Bay, and the region is therefore important for studies of glacial isostatic adjustment (GIA) that aim to constrain both the ice sheet history and Earth rheology. The west coast of Hudson Bay has low topographic relief, and following deglaciation, much of this region was submerged as ocean ente...
Article
Full-text available
We examine absolute gravity (AG) and vertical Global Positioning System (GPS) time series between 1995 and 2010 at eight collocated sites in mid-continent North America. The comparison of AG and GPS rates aligned to ITRF2005 yields a gravity/uplift ratio of -0.17 ± 0.01 μGal mm-1 (1 μGal = 10 nm s-2) and an intercept of -0.1 ± 0.5 mm yr-1. In contr...
Article
High-precision absolute gravity (AG) observations are sensitive to vertical motion of the observation site as well as mass redistribution within (and below) the underlying deforming crust. The deformation gravity gradient (DGG) may be defined as the ratio of the time rate of change of surface gravity (g-dot) to vertical crustal velocity (h-dot) and...
Article
Full-text available
Molluscs, sediment lithology, and published sub-bottom profiles are used to deduce sea levels, outline the influence of glacially induced crustal displacement, and reconstruct the paleoenvironment of the northeast Pacific late Quaternary coastline. Geo-spatial modelling shows subaerially exposed land that could have been inhabited by plants and ani...
Article
Full-text available
Swath bathymetry from the northern Cascadia margin offshore Vancouver Island, Canada reveals several submarine landslides on the seaward slopes of the deformation frontal ridges. The slides occur in the thick accretionary prism of the subducting Juan de Fuca and Explorer plates. Possible trigger mechanisms for the slope failures include strong eart...
Article
Postglacial rebound (PGR) or glacial isostatic adjustment (GIA) models for Antarctica have been proposed and revised for many years but only recently has GPS crustal uplift data been available to compare to model predictions. Bevis et al. (2009) described new observations of crustal uplift in Antarctica and compared the results to GIA model predict...
Article
The northwest coast of Hudson Bay is in the central region of the former Laurentide ice sheet. The region is therefore important for inferring ice sheet history and thickness and Earth rheology through analysis of the Earth's glacial isostatic adjustment (GIA) response. Before this study, however, relatively few (14) relative sea-level (RSL) observ...
Article
The IJ05 Antarctic ice sheet history is employed to drive a suite of approximately one thousand two-layered, laterally-homogeneous spherical Earth models and generate predictions of Antarctic crustal uplift due to glacial isostatic adjustment (GIA). GPS data collected between 1996 and 2010 on the flanks of the West Antarctic Rift System are used to...
Article
Full-text available
The effect of regional ocean loading on predicted rates of crustal uplift and gravitational change due to glacial isostatic adjustment (GIA) is determined for Antarctica. The effect is found to be significant for the ICE-3G and ICE-5G loading histories (up to −8 mm/year and −3 mm/year change in uplift rate and −3 cm/year and −1 cm/year equivalent w...
Article
We present projections of relative sea-level rise in the 21st century for communities in the Canadian Arctic. First, for selected communities, we determine the sea-level fingerprinting response from Antarctica, Greenland, and mountain glaciers and ice caps. Then, for various published projections of global sea-level change in the 21st century, we d...
Article
The IJ05 Antarctic ice sheet history is employed to drive a suite of approximately one thousand two-layered, laterally-homogeneous spherical Earth models and generate predictions of Antarctic crustal uplift due to glacial isostatic adjustment (GIA). Comparison of the predictions with GPS-derived crustal uplift rates, mainly from southern Victoria L...
Article
Forty-eight new and previously published radiocarbon ages constrain deglacial and postglacial sea levels on southern Vancouver Island, British Columbia. Sea level fell rapidly from its high stand of about +75 m elevation just before 14 000 cal BP (12 000 radiocarbon yrs BP) to below the present shoreline by 13 200 cal BP (11 400 radiocarbon years B...
Article
The effect of regional ocean loading on predicted rates of crustal uplift and gravitational change due to glacial isostatic adjustment (GIA) is determined for Antarctica. The effect is found to be large (up to -8 mm/yr change in uplift rate and -3 cm/yr water equivalent gravity change) for the ICE-3G loading history but is much smaller (+1 mm/yr; +...
Article
Full-text available
New data from Barkley Sound on the west coast of Vancouver Island, British Columbia, and from the mainland coast north of Vancouver add to the inventory of constraints on relative sea level during and after the collapse of the Cordilleran Ice Sheet (CIS). Previously published observations lie on a northwest-southeast profile along the east coast of...
Article
Long wavelength gravity changes associated with imbalance of the cryosphere and other interannual and secular processes are now being mapped from space using GRACE (Gravity Recovery and Climate Experiment) mission data. The gravity changes are supplemented by constraints that come from bounds on Earth rotation and the drift between the Earth's cent...
Article
Full-text available
Late glacial sea level curves located in the Cascadia subduction zone (CSZ) fore arc in southwestern British Columbia show that glacial isostatic adjustment (GIA) was rapid when the Cordilleran Ice Sheet collapsed in the late Pleistocene. GIA modeling with a linear Maxwell rheology indicates that the observations can be equally well fit across a wi...
Article
The ice cover grounded to the Antarctic Peninsula (AP) today represents but a small fraction of water attached to the continent of Antarctica (? 0.3 % by mass). However, the more northern latitude of the Peninsula renders its grounded water mass many times more volatile that is ice mass locked in the thick ice sheet cover south of 70-75˚ S. If ice...
Article
Late-glacial sea-level curves located above the Cascadia Subduction Zone (CSZ) in southwestern British Columbia show that glacio-isostatic adjustment (GIA) was rapid when the Cordilleran ice sheet collapsed in the late Pleistocene. GIA models developed to explain the sea-level observations employ an ice sheet model modified from previous studies. T...
Article
The effect of relatively high fidelity regional ocean loading in Antarctica on predicted rates of glacial isostatic adjustment (GIA) is quantified for the IJ05 surface loading history. The recently developed IJ05 model was designed to incorporate the growing compilation of geological and glaciological constraints on the evolution of the Antarctic i...
Article
Data from the Gravity Recovery and Climate Experiment (GRACE) have recently been used to infer mass change rates of the Antarctic ice sheet. A leading source of uncertainty in interpretation of the GRACE measurements is the poorly constrained Glacial Isostatic Adjustment (GIA) correction. We use the recent IJ05 ice sheet history to load a suite of...