The North American Cordillera: A Color Shaded-Relief Map in Oblique Mercator Projection about the Pacific-North America Pole of Rotation, Scale Circa 1:5,000,000

This is the second in a series of papers intended to establish a Lower Jurassic ammonite zonation that takes into account the biostratigraphic and biogeographic peculiarities of the North American succession. In North America the lower boundary of the Toarcian is drawn at the first appearance of Dactylioceras above the last occurrence of Amaltheus and Fanninoceras. The lower Toarcian is represented by the Kanense Zone; the middle Toarcian by the Planulata and Crassicosta zones; and the upper Toarcian by the Hillebrandti and Yakounensis zones. Section 5 on the Yakoun River in the Queen Charlotte Islands is designated the stratotype for the Planulata, Crassicosta, and Hillebrandti zones; section 3 on the Yakoun River is designated the stratotype for the Yakounensis Zone; an ideal stratotype for the Kanense Zone is not presently known. Reference sections further illustrating the faunal associations that characterize the zones are designated in eastern Oregon (Snowshoe Formation) and northern British Columbia (Spatsizi Group). The Dactylioceratidae, Harpoceratinae, and Hildoceratinae provide the most important zonal indicators for the lower Toarcian; Dactylioceratidae, Phymatoceratinae, and Bouleiceratinae for the middle Toarcian; and Phymatoceratinae, Grammoceratinae, and Hammatoceratinae for the upper Toarcian. Phymatoceras hillebrandti is described as a new species.

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Intraseasonal and Interannual Variability in North American Storm Tracks and Its Relationship to Equatorial Pacific Variability

Monthly Weather Review ◽

10.1175/mwr-d-12-00322.1 ◽

2013 ◽

Vol 141 (10) ◽

pp. 3610-3625 ◽

Cited By ~ 42

Author(s):

Kevin M. Grise ◽

Seok-Woo Son ◽

John R. Gyakum

Keyword(s):

North America ◽

Interannual Variability ◽

North American ◽

Southern Oscillation ◽

Extratropical Cyclones ◽

The North ◽

The Pacific ◽

Cyclone Tracks ◽

Lagrangian Tracking ◽

The North Atlantic Oscillation

Abstract Extratropical cyclones play a principal role in wintertime precipitation and severe weather over North America. On average, the greatest number of cyclones track 1) from the lee of the Rocky Mountains eastward across the Great Lakes and 2) over the Gulf Stream along the eastern coastline of North America. However, the cyclone tracks are highly variable within individual winters and between winter seasons. In this study, the authors apply a Lagrangian tracking algorithm to examine variability in extratropical cyclone tracks over North America during winter. A series of methodological criteria is used to isolate cyclone development and decay regions and to account for the elevated topography over western North America. The results confirm the signatures of four climate phenomena in the intraseasonal and interannual variability in North American cyclone tracks: the North Atlantic Oscillation (NAO), the El Niño–Southern Oscillation (ENSO), the Pacific–North American pattern (PNA), and the Madden–Julian oscillation (MJO). Similar signatures are found using Eulerian bandpass-filtered eddy variances. Variability in the number of extratropical cyclones at most locations in North America is linked to fluctuations in Rossby wave trains extending from the central tropical Pacific Ocean. Only over the far northeastern United States and northeastern Canada is cyclone variability strongly linked to the NAO. The results suggest that Pacific sector variability (ENSO, PNA, and MJO) is a key contributor to intraseasonal and interannual variability in the frequency of extratropical cyclones at most locations across North America.

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A new species of Placiphorella (Polyplacophora: Mopaliidae) from the North American Pacific coast

The Festivus ◽

10.54173/f512103 ◽

2019 ◽

Vol 51 (2) ◽

pp. 103-107

Author(s):

Roger Clark

Keyword(s):

New Species ◽

North America ◽

North American ◽

Deep Sea ◽

Pacific Coast ◽

The North ◽

The Pacific ◽

A New Species

A new deep-sea chiton of the genus Placiphorella Dall, 1879, Placiporella laurae n. sp. is described from the Pacific coast of North America. It is compared with its congener Placiphorella pacifica Berry, 1919, from which it differs primarily by having granular valves, lacking false beaks, a papillose girdle, and the characteristics of its girdle spicules

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North American Winter Dipole: Observed and Simulated Changes in Circulations

Atmosphere ◽

10.3390/atmos10120793 ◽

2019 ◽

Vol 10 (12) ◽

pp. 793 ◽

Cited By ~ 2

Author(s):

Yu-Tang Chien ◽

S.-Y. Simon Wang ◽

Yoshimitsu Chikamoto ◽

Steve L. Voelker ◽

Jonathan D. D. Meyer ◽

...

Keyword(s):

North America ◽

North American ◽

Large Scale ◽

Climate Model ◽

Model Simulations ◽

The North ◽

Weather Events ◽

The Pacific ◽

Climate Model Simulations ◽

Northwestern North America

In recent years, a pair of large-scale circulation patterns consisting of an anomalous ridge over northwestern North America and trough over northeastern North America was found to accompany extreme winter weather events such as the 2013–2015 California drought and eastern U.S. cold outbreaks. Referred to as the North American winter dipole (NAWD), previous studies have found both a marked natural variability and a warming-induced amplification trend in the NAWD. In this study, we utilized multiple global reanalysis datasets and existing climate model simulations to examine the variability of the winter planetary wave patterns over North America and to better understand how it is likely to change in the future. We compared between pre- and post-1980 periods to identify changes to the circulation variations based on empirical analysis. It was found that the leading pattern of the winter planetary waves has changed, from the Pacific–North America (PNA) mode to a spatially shifted mode such as NAWD. Further, the potential influence of global warming on NAWD was examined using multiple climate model simulations.

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Ancestral trans−North American Bell River system recorded in late Oligocene to early Miocene sediments in the Labrador Sea and Canadian Great Plains

Geological Society of America Bulletin ◽

10.1130/b35903.1 ◽

2021 ◽

Author(s):

Julia I. Corradino ◽

Alex Pullen ◽

Andrew L. Leier ◽

David L. Barbeau Jr. ◽

Howie D. Scher ◽

...

Keyword(s):

North America ◽

Great Plains ◽

North American ◽

Detrital Zircon ◽

Detrital Zircons ◽

Labrador Sea ◽

Western Canada ◽

Zircon Age ◽

North American Cordillera ◽

The North

The Bell River hypothesis proposes that an ancestral, transcontinental river occupied much of northern North America during the Cenozoic Era, transporting water and sediment from the North American Cordillera to the Saglek Basin on the eastern margin of the Labrador Sea. To explore this hypothesis and reconstruct Cenozoic North American drainage patterns, we analyzed detrital zircon grains from the Oligocene−Miocene Mokami and Saglek formations of the Saglek Basin and Oligocene−Miocene fluvial conglomerates in the Great Plains of western Canada. U-Pb detrital zircon age populations in the Mokami and Saglek formations include clusters at <250 Ma, 950−1250 Ma, 1600−2000 Ma, and 2400−3200 Ma. Detrital zircons with ages of <250 Ma were derived from the North American Cordillera, supporting the transcontinental Bell River hypothesis. Oligocene−Miocene fluvial strata in western Canada contain detrital zircon age populations similar to those in the Saglek Basin and are interpreted to represent the western headwaters of the ancient Bell River drainage. Strontium-isotope ratios of marine shell fragments from the Mokami and Saglek formations yielded ages between 25.63 and 18.08 Ma. The same shells have εNd values of −10.2 to −12.0 (average = −11.2), which are consistent with values of Paleozoic strata in western North America but are more radiogenic than the modern Labrador Current, Labrador Sea Water, and North Atlantic Deep Water values (εNd ∼−12 to −25). As a freshwater source, the existence and termination of the Bell River may have been important for Labrador Sea circulation, stratification, and chemistry.

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Which MJO Events Affect North American Temperatures?

Monthly Weather Review ◽

10.1175/mwr-d-13-00118.1 ◽

2013 ◽

Vol 141 (11) ◽

pp. 3840-3850 ◽

Cited By ~ 28

Author(s):

Carl J. Schreck ◽

Jason M. Cordeira ◽

David Margolin

Keyword(s):

North America ◽

North American ◽

North Pacific ◽

Wave Breaking ◽

La Niña ◽

Teleconnection Patterns ◽

The North ◽

La Nina ◽

The Pacific ◽

The North Pacific

Abstract Tropical convection from the Madden–Julian oscillation (MJO) excites and amplifies extratropical Rossby waves around the globe. This forcing is reflected in teleconnection patterns like the Pacific–North American (PNA) pattern, and it can ultimately result in temperature anomalies over North America. Previous studies have not explored whether the extratropical response might vary from one MJO event to another. This study proposes a new index, the multivariate PNA (MVP), to identify variations in the extratropical waveguide over the North Pacific and North America that might affect the response to the MJO. The MVP is the first combined EOF of 20–100-day OLR, 850-hPa streamfunction, and 200-hPa streamfunction over the North Pacific and North America. The North American temperature patterns that follow each phase of the MJO change with the sign of the MVP. For example, real-time multivariate MJO (RMM) phase 5 usually leads to warm anomalies over eastern North America. This relationship was only found when the MVP was negative, and it was not associated with El Niño or La Niña. RMM phase 8, on the other hand, usually leads to cold anomalies. Those anomalies only occur if the MVP is positive, which happens somewhat more frequently during La Niña years. Composite analyses based on combinations of the MJO and the MVP show that variability in the Pacific jet and its associated wave breaking play a key role in determining whether and how the MJO affects North American temperatures.

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Piracy in Colonial North America

Oxford Research Encyclopedia of American History ◽

10.1093/acrefore/9780199329175.013.813 ◽

2020 ◽

Author(s):

Mark G. Hanna

Keyword(s):

North America ◽

New England ◽

North American ◽

18Th Century ◽

Historical Narrative ◽

British North America ◽

American Colonies ◽

The North ◽

The Pacific ◽

British North American

Historians of colonial British North America have largely relegated piracy to the marginalia of the broad historical narrative from settlement to revolution. However, piracy and unregulated privateering played a pivotal role in the development of every English community along the eastern seaboard from the Carolinas to New England. Although many pirates originated in the British North American colonies and represented a diverse social spectrum, they were not supported and protected in these port communities by some underclass or proto-proletariat but by the highest echelons of colonial society, especially by colonial governors, merchants, and even ministers. Sea marauding in its multiple forms helped shape the economic, legal, political, religious, and cultural worlds of colonial America. The illicit market that brought longed-for bullion, slaves, and luxury goods integrated British North American communities with the Caribbean, West Africa, and the Pacific and Indian Oceans throughout the 17th century. Attempts to curb the support of sea marauding at the turn of the 18th century exposed sometimes violent divisions between local merchant interests and royal officials currying favor back in England, leading to debates over the protection of English liberties across the Atlantic. When the North American colonies finally closed their ports to English pirates during the years following the Treaty of Utrecht (1713), it sparked a brief yet dramatic turn of events where English marauders preyed upon the shipping belonging to their former “nests.” During the 18th century, colonial communities began to actively support a more regulated form of privateering against agreed upon enemies that would become a hallmark of patriot maritime warfare during the American Revolution.

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Geology, Mantle Tomography, and Inclination Corrected Paleogeographic Trajectories Support Westward Subduction During Cretaceous Orogenesis in the North American Cordillera

Geoscience Canada ◽

10.12789/geocanj.2014.41.032 ◽

2014 ◽

Vol 41 (2) ◽

pp. 207 ◽

Cited By ~ 6

Author(s):

Robert S. Hildebrand

Keyword(s):

North America ◽

North American ◽

Passive Margin ◽

Canadian Cordillera ◽

Western North America ◽

Geological Evidence ◽

North American Cordillera ◽

The North ◽

Independent Verification ◽

Haute Résolution

Geological evidence, including the presence of two passive margin platforms, juxtaposed and mismatched deformation between North America and more outboard terranes, as well as the lack of rift deposits, suggest that North America was the lower plate during both the Sevier and Laramide events and that subduction dipped westward beneath the Cordilleran Ribbon Continent (Rubia). Terranes within the composite ribbon continent, now present in the Canadian Cordillera, collided with western North America during the 125–105 Ma Sevier event and were transported northward during the ~80–58 Ma Laramide event, which affected the Cordillera from South America to Alaska. New high-resolution mantle tomography beneath North America reveals a huge slab wall that extends vertically for over 1000 km, marks the site of long-lived subduction, and provides independent verification of the westward-dipping subduction model. Other workers analyzed paleogeographic trajectories and concluded that the initial collision took place in Canada at about 160 Ma – a time and place for which there is no deformational thickening on the North American platform – and later farther west where subduction was not likely westward, but eastward. However, by utilizing a meridionally corrected North American paleogeographic trajectory, coupled with the geologically most reasonable location for the initial deformation, the position of western North America with respect to the relict superslab parsimoniously accounts for the timing and extents of both the Sevier and Laramide events. SOMMAIRELes indications géologiques, en particulier la présence de deux marges de plateforme passives, de déformations adjacentes non-conformes entre l’Amérique du Nord et les terranes extérieurs, ainsi que l’absence de gisements de rift, permet de croire que l’Amérique du Nord était la plaque sous-jacente durant les événements de Sevier et de Laramide et que la subduction plongeait vers l’ouest sous le continent rubané de la Cordillères (Rubia). Les terranes du continent rubané composite, maintenant au sein de la Cordillère canadienne, sont entrés en collision avec l’ouest de l’Amérique du Nord durant l’événement Sevier (125-105 Ma), et ont été transportés vers le nord durant l’événement Laramide (~80–58 Ma), laquelle a affecté la Cordillère, de l’Amérique du Sud à l’Alaska. Une nouvelle tomographie haute résolution du manteau sous l’Amérique du Nord montre la présence d’un gigantesque mur de plaques vertical qui s’étend sur 1 000 km, marque le site d’une subduction de longue haleine, et offre une validation indépendante du modèle d’une subduction à pendage vers l’ouest. D’autres chercheurs ont analysé les trajectoires paléogéographiques et conclu que la collision initiale s’est produite au Canada vers 160 Ma – un moment et un endroit sans épaississement par déformation sur la plateforme d’Amérique du Nord – et plus tard plus à l’ouest, là où la subduction n’était vraisemblablement pas vers l’ouest, mais vers l’est. Cela dit, en considérant une trajectoire paléogéographique de l’Amérique du Nord corrigée longitudinalement, avec la position géologique la plus probable de la déformation initiale, la position de la portion ouest de l’Amérique du Nord par rapport aux restes de la super-plaque explique alors facilement la chronologie et l’étendue des épisodes Sevier et Laramide.

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Eriosomatine aphids (Hemiptera: Aphididae: Eriosomatinae) associated with moss and roots of conifer and willow in forests of the Pacific Northwest of North America

The Canadian Entomologist ◽

10.4039/tce.2012.49 ◽

2012 ◽

Vol 144 (4) ◽

pp. 555-576 ◽

Cited By ~ 2

Author(s):

K.S. Pike ◽

G. Graf ◽

R.G. Foottit ◽

H.E.L. Maw ◽

C. von Dohlen ◽

...

Keyword(s):

North America ◽

Pacific Northwest ◽

North American ◽

Deoxyribonucleic Acid ◽

Sequence Matching ◽

The North ◽

The Pacific ◽

First Time

AbstractApterous adult morphs of eriosomatine aphids associated with moss (Bryophyta) and/or roots of conifer (Pinaceae) or willow (Salix Linnaeus (Salicaceae)) in forests of the North American Pacific Northwest including Alaska are described, illustrated, and keyed. In total, seven species (Clydesmithia canadensis Danielsson, Melaphis rhois (Fitch) (moss only feeder), Pachypappa rosettei (Maxson), Pachypappa sacculi (Gillette), Prociphilus americanus (Walker) (fir root only feeder), Prociphilus xylostei (De Geer), and Thecabius populimonilis (Riley)) are characterised from their secondary host habitats. Secondary host forms of C. canadensis and T. populimonilis are described for the first time. The morphotypes from the secondary hosts were confirmed through deoxyribonucleic acid sequence matching with those from the primary hosts.

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Uplift and exhumation in Haida Gwaii driven by terrane translation and transpression along the southern Queen Charlotte fault, Canada

Geology ◽

10.1130/g47364.1 ◽

2020 ◽

Vol 48 (9) ◽

pp. 908-912

Author(s):

Philip Schoettle-Greene ◽

Alison R. Duvall ◽

Ann Blythe ◽

Eric Morley ◽

William Matthews ◽

...

Keyword(s):

North America ◽

North American ◽

North American Plate ◽

Cascadia Subduction Zone ◽

Haida Gwaii ◽

Crustal Shortening ◽

Basin Inversion ◽

Subduction Initiation ◽

The North ◽

The Pacific

Abstract The mountainous archipelago of Haida Gwaii abuts the transpressive Pacific–North American plate margin north of the Cascadia subduction zone (northwestern North America). Topography on Haida Gwaii has been attributed to either dynamic uplift supported by subduction initiation or crustal shortening driven by shear adjacent the plate-bounding Queen Charlotte fault. In order to resolve how intraplate strain is accommodated, we obtained thermochronometry data from 20 bedrock samples on Haida Gwaii, including zircon (U-Th)/He, apatite (U-Th-Sm)/He, and apatite fission-track dates. With dates ranging from 5 to 60 Ma, we interpret exhumation rates increasing in proximity to the Queen Charlotte fault and leading to a maximum of 6 km of exhumation since 20 Ma. The onset of exhumation significantly predates the purported initiation of subduction, precluding a direct relationship between subduction initiation and the development of topography in the archipelago. Instead, exhumation onset correlates with passage of the Yakutat terrane, suggesting that North America was deformed and Haida Gwaii uplifted during terrane translation. Steady or slightly decreasing exhumation rate since the Miocene is at odds with estimated increases to intraplate convergence over this time, ruling out crustal shortening in Haida Gwaii as the only response to transpression between North America and the Pacific. From this, we conclude that plate convergence is accommodated through basin inversion and internal shortening in the North American and Pacific plates as well as potential underthrusting of the Pacific plate beneath North America.

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