scholarly journals Crustal structure and earthquake hazards of the subduction zone in southwestern British Columbia and western Washington

2006 ◽  
Author(s):  
Michael A. Fisher ◽  
Roy D. Hyndman ◽  
Samuel Y. Johnson ◽  
Thomas M. Brocher ◽  
Robert S. Crosson ◽  
...  
2020 ◽  
Vol 16 (5) ◽  
pp. e425-e432 ◽  
Author(s):  
Todd A. Yezefski ◽  
Dan Le ◽  
Leo Chen ◽  
Caroline H. Speers ◽  
Shasank Chennupati ◽  
...  

PURPOSE: Few studies have directly compared health care utilization, costs, and outcomes between patients treated in the US multipayer health system and Canada’s single-payer system. Using cancer registry and claims data, we assessed treatment types, costs, and survival for patients with metastatic colorectal cancer (mCRC) in Western Washington State (WW) and British Columbia (BC). MATERIALS AND METHODS: Patients age ≥ 18 years diagnosed with mCRC in 2010 and later were identified from the BC Cancer database and a regional database linking WW SEER to claims from Medicare and two large commercial insurers. Demographics, treatment characteristics, costs of systemic therapy, and survival data were obtained from these databases and compared between the two regions. RESULTS: A total of 1,592 patients from BC and 901 from WW were included in the study. Median age was similar (BC, 66 years; WW, 63 years), but patients in BC were more likely to be male (57.1% v 51.2%; P ≤ .01) and to have de novo metastatic disease (61.0% v 38.3%; P ≤ .01). The use of radiation therapy was similar between regions (BC, 31.2%; WW, 33.9%; P = .18), but primary tumor resection was more common in BC (74.1% v 66.3%; P ≤ .01) as was hepatic metastasectomy (12.4% v 2.3%; P ≤ .01). Similar percentages of patients received systemic therapy (BC, 68.8%; WW, 67.1%; P = .40), but costs were significantly higher for first-line systemic therapy in WW ($6,226 v $15,792 per patient per month; P ≤ .01). Median overall survival was similar (BC, 16.9 months; WW, 18 months). CONCLUSION: Cost of systemic therapy for mCRC was significantly higher for patients in WW than in BC, but this did not translate to a difference in overall survival.


2007 ◽  
Vol 170 (2) ◽  
pp. 800-812 ◽  
Author(s):  
R. K. Dash ◽  
G. D. Spence ◽  
M. Riedel ◽  
R. D. Hyndman ◽  
T. M. Brocher

1995 ◽  
Vol 11 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Brian F. Atwater ◽  
Alan R. Nelson ◽  
John J. Clague ◽  
Gary A. Carver ◽  
David K. Yamaguchi ◽  
...  

Earthquakes in the past few thousand years have left signs of land-level change, tsunamis, and shaking along the Pacific coast at the Cascadia subduction zone. Sudden lowering of land accounts for many of the buried marsh and forest soils at estuaries between southern British Columbia and northern California. Sand layers on some of these soils imply that tsunamis were triggered by some of the events that lowered the land. Liquefaction features show that inland shaking accompanied sudden coastal subsidence at the Washington-Oregon border about 300 years ago. The combined evidence for subsidence, tsunamis, and shaking shows that earthquakes of magnitude 8 or larger have occurred on the boundary between the overriding North America plate and the downgoing Juan de Fuca and Gorda plates. Intervals between the earthquakes are poorly known because of uncertainties about the number and ages of the earthquakes. Current estimates for individual intervals at specific coastal sites range from a few centuries to about one thousand years.


Science ◽  
1987 ◽  
Vol 236 (4798) ◽  
pp. 162-168 ◽  
Author(s):  
T. H. HEATON ◽  
S. H. HARTZELL

1977 ◽  
Vol 14 (7) ◽  
pp. 1611-1624 ◽  
Author(s):  
John R. Griffiths

Three time–space profiles have been constructed using geologic data from British Columbia between 49° N and 56° N. They illustrate variations across the Cordillera, (1) in the stratigraphic and tectonic setting of volcanism, (2) in the age and modal type of granitoids, and (3) in the distribution and types of copper and lead deposits related to volcanic and plutonic rocks. These profiles provide the basis for a plate tectonic synthesis of the Mesozoic–Cenozoic geology, illustrated by six true-scale cross sections.The preferred model has, in the Triassic, two eastward-dipping subduction zones, giving rise to the copper-rich Karmutsen and Nicola–Takla volcanics respectively. After collision of the two volcanic belts by the Early Jurassic, a single eastward-dipping subduction zone remained active until the Eocene. Magmas produced by partial melting and fractionation of subducted lithosphere occurred across the western 300 km of the Cordillera, leading to thickening of the crust, and eventually to anatectic melting to generate large batholiths now containing pendants of volcanics. Jurassic and later geologic and metallogenic events across the eastern 500 km of the Cordillera are the results of an increased heat flux through inhomogeneous crust of varying thickness, comprised of relict ocean floor, continental margin sediments, older volcanics, and ancient cratonic basement. This results in patterns of metamorphism, volcanism, and plutonism which have no simple spatial relationship to the subduction zone.


Geology ◽  
1998 ◽  
Vol 26 (3) ◽  
pp. 199 ◽  
Author(s):  
Tom Parsons ◽  
Anne M. Trehu ◽  
James H. Luetgert ◽  
Kate Miller ◽  
Fiona Kilbride ◽  
...  

2013 ◽  
Vol 50 (7) ◽  
pp. 746-760 ◽  
Author(s):  
Randolph J. Enkin ◽  
Audrey Dallimore ◽  
Judith Baker ◽  
John R. Southon ◽  
Tara Ivanochko

Annually laminated sediments from the anoxic inner basin of Effingham Inlet, Pacific coast of Vancouver Island, British Columbia, Canada, yield a high-resolution 42 m paleoenvironmental record, from the present to about 14 ka 14C BP (17 ka cal BP). A new age model, based on 68 radiocarbon dates from twigs and small plant material, from the 40 m core MD02-2494 and 2 m freeze cores from the surface, is anchored by the Mazama Ash and varve counting. A Poisson-process sedimentation model is used, applying a new method to determine the Poisson k value, giving a realistic age model compatible with the multi-proxy core data. Twenty-one “seismites”, which are lithofacies in the Effingham cores that may be representative of seismically triggered mass-wasting events, are identified and dated precisely, then compared with the chronology of the deep-sea turbidite record farther south in the Cascadia Subduction Zone (CSZ), to determine if regional sediment disturbances can be identified. With 16 proposed correlations, Effingham seismite ages are 169 ± 206 years older than turbidite ages estimated largely by radiocarbon analysis of foraminifera in hemipelagic deposits.


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