Geological Survey research 1965, Chapter C

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doi:10.3133/pp525c

Cited by 3 publications

(4 citation statements)

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“…Floods speeding through this route eroded midvalley knobs and bedrock valley slopes, deposited massive foreset-bedded gravel bars, some mantled with giant current dunes, and left valley-blocking eddy bars in tributary mouths (Flint, 1936;Richmond et al, 1965;Weis and Richmond, 1965;Weis, 1968; J o u r n a l P r e -p r o o f Baker, 1973;O'Connor and Baker, 1992;Breckenridge and Othberg, 1998a, b;Lewis et al, 2002;Waitt et al, 2016). High eddy bars, divide crossings, scabland, and ice-rafted erratics define maximum-flood stages declining from 810-820 m near the southern tip of Lake Pend Oreille to ~780 m near Spokane and downstream (Table 3; Figure 8; Baker, 1973, p.17;O'Connor and Baker, 1992, p. 274).…”

Section: Spokane-rathdrum Valleysmentioning

confidence: 99%

The Missoula and Bonneville floods—A review of ice-age megafloods in the Columbia River basin

O’Connor

Baker

Waitt

et al. 2020

Earth-Science Reviews

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The Channeled Scabland of eastern Washington State, USA, brought megafloods to the scientific forefront. A 30,000-km2 landscape of coulees and cataracts carved into the region's loess-covered basalt attests to overwhelming volumes of energetic water. The scarred landscape, garnished by huge boulder bars and far-travelled ice-rafted erratics, spurred J Harlen Bretz's vigorously disputed flood hypothesis in the 1920s. First known as the Spokane flood, it was rebranded the Missoula flood once understood that the water came from glacial Lake Missoula, formed when the Purcell Trench lobe of the last-glacial Cordilleran ice sheet dammed the Clark Fork valley in northwestern Idaho with ice a kilometer thick. Bretz's flood evidence in the once-remote Channeled Scabland, widely seen and elaborated by the 1950s, eventually swayed consensus for cataclysmic flooding. Missoula flood questions then turned to some that continue today: how many? when? how big? what routes? what processes?The Missoula floods passed through eastern Washington by a multitude of valleys, coulees and scabland tracts, some contemporaneously, some sequentially. Routings and their timing depended on the positions of various lobes of the multi-pronged Cordilleran ice sheet and the erosional development of the channels themselves. The first floods mostly followed the big bend of Columbia valley looping through north-central Washington. But the south-advancing Okanogan ice lobe soon blocked that path, forming long-lasting glacial Lake Columbia in the impounded Columbia valley. Missoula floods into this lake were diverted south out of the Columbia valley and into eastern Washington coulees and scabland tracts. At least four floods entered Moses Coulee, but then as the Okanogan lobe advanced over and blocked the head of that coulee, more eastern paths took the water, including Grand Coulee and the Telford-Crab-Creek and Cheney-Palouse scabland tracts. Flood routing also depended on the erosion of the coulees. At some point, headward erosion of upper Grand Coulee lowered the divide saddle between the west-running Columbia valley and the deep and wide Grand Coulee heading southwest. Still uncertain is when this happened and the consequences with respect to the stage and extent of glacial Lake Columbia and to flood access to the other, higher, flood routes. Downstream, all flood routes converged into Pasco Basin, flowed through Wallula Gap and the Columbia River Gorge into the Pacific Ocean, following submarine canyons and depositing sediment layers on abyssal plains.Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.and perhaps older ones affected the Snake River Plain, some likely sourced in lakes dammed by alpine glaciers in central Idaho.

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Section: Spokane-rathdrum Valleysmentioning

confidence: 99%

The Missoula and Bonneville floods—A review of ice-age megafloods in the Columbia River basin

O’Connor

Baker

Waitt

et al. 2020

Earth-Science Reviews

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“…A breakdown from uniformity of the distributions of either or both of these types of spots then needs to be investigated to validate the null hypothesis of isotropy. We use the concept of the orientation matrix introduced by Watson (1965) [14] and Scheidegger (1965) [15], to probe any violations of uniformity of the distributions of hot and cold spots over the CMB sky. The method is unique in its nature, since if there is any non-uniformity present in the data, it provides a geometric description of the nonuniformity in terms of clustering or girdling (ring structure) and an additional measure of the magnitude of such a deviation from uniformity in terms of the so-called strength parameter.…”

Section: Jcap06(2022)006mentioning

confidence: 99%

“…. , n. Scheidegger (1965) [15] used the principal eigenvector of the normalised unit-mass orientation matrix (i.e, T /n) to find a 'mean' axis, while Watson (1965) [14] used the eigenvalues of T to classify non-uniform placements of data points on a 2-sphere. Woodcock (1977) [51] defined two kinds of eigenvalue ratios to quantify the shape and strength of such non-uniformity.…”

Section: Jcap06(2022)006 2 Estimatorsmentioning

confidence: 99%

“…Under this assumption, the hot spots and cold spots of the CMB are expected to be uniformly distributed over a 2-sphere. We use the orientation matrix, first proposed by Watson (1965) and Scheidegger (1965) and associated shape and strength parameters (Woodcock, 1977) to analyse whether the hot and cold spots of the observed CMB temperature anisotropy field are uniformly placed. We demonstrate the usefulness of our estimators by using simulated toy models containing nonuniform data.…”

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Isotropy statistics of CMB hot and cold spots

Khan

Saha

2022

J. Cosmol. Astropart. Phys.

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Statistical Isotropy of the Cosmic Microwave Background (CMB) radiation has been studied and debated extensively in recent years. Under this assumption, the hot spots and cold spots of the CMB are expected to be uniformly distributed over a 2-sphere. We use the orientation matrix, first proposed by Watson (1965) and Scheidegger (1965) and associated shape and strength parameters (Woodcock, 1977) to analyse whether the hot and cold spots of the observed CMB temperature anisotropy field are uniformly placed. We demonstrate the usefulness of our estimators by using simulated toy models containing non-uniform data. We apply our method on several foreground minimized CMB maps observed by WMAP and Planck over large angular scales. The shape and strength parameters constrain geometric features of possible deviations from uniformity (isotropy) and the power of the anomalous signal. We find that distributions of hot or cold spots in cleaned maps show no unusual signature of clustering or girdling. Instead, we notice a strikingly uniform distribution of hot spots over the full sky. The signal remains robust with respect to the four cleaned maps used and presence or absence of the non-Gaussian cold spot (NGCS). On the partial sky with WMAP KQ75 and Planck U73 masks we find anomalously low strength of non-uniformity for cold spots which is found to be robust with respect to various cleaning methods, masks applied, instruments, frequencies, and the presence or absence of the NGCS. Interestingly we find that the signal of anomalously weak non-uniformity could be due to contributions from the quadrupole and octupole and may be related with the low CMB temperature variance anomaly.

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Styles of mesoscale brittle deformations associated with the Miocene folding of the Taishu Group, Tsushima, between the Japan Sea and East China Sea backarc basins

2021

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The Taishu Group is a folded, Eocene-Lower Miocene, thick sedimentary package exposed widely on Tsushima Island between the Japan Sea and East China Sea. This location makes the strata important to understand tectonics and paleo-environments in the Far East, but the timing of the folding is controversial. We studied the styles of brittle deformations of the strata. It was found that flextural-slip folds were dominant. Mesoscale faults were classified into two groups: NE-SW trending reverse faults and NW-SE trending strike-slip faults. Members of both the groups showed movements largely perpendicular to the fold axes. The latter group consisted of sinistral and dextral faults.Accordingly, we interpreted that they were transfer faults activated during the folding.Consequently, mesoscale faults and flexural-slip faults evidence the map-scale plane strain of the Taishu Group in the plane perpendicular to the NE-trending fold axes. There were few transpressional deformations in the group. This is inconsistent with the transpression hypothesis for explaining the simultaneous folding and Japan Sea opening. Another hypothesis in which the folds in Tsushima are regarded as an onshore part of the Taiwan-Shinji fold belt is inconsistent with the timing of folding suggested by mining geologists to be consistent with and contemporaneous with this deformation. On the other hand, we found that dolerite dikes and sills were involved in the folding. Therefore, we conclude that the folding began during the late Early Miocene time and climaxed during the ore mineralization at around 15 Ma. We suggest that the folding in Tsushima was the easternmost manifestation of the compressional regime around the Yellow Sea and East China Sea in the Early to early Middle Miocene, and that the compression was brought about by the arrival of the Philippine Sea plate to initiate buoyant subduction under Kyushu.

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Geological Survey research 1965, Chapter C

Cited by 3 publications

References 58 publications

The Missoula and Bonneville floods—A review of ice-age megafloods in the Columbia River basin

The Missoula and Bonneville floods—A review of ice-age megafloods in the Columbia River basin

Isotropy statistics of CMB hot and cold spots

Styles of mesoscale brittle deformations associated with the Miocene folding of the Taishu Group, Tsushima, between the Japan Sea and East China Sea backarc basins

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