Extending the terrestrial depositional record of marine geohazards in coastal NW British Columbia

2018 ◽  
Vol 477 (1) ◽  
pp. 277-292 ◽  
Author(s):  
David Huntley ◽  
Peter Bobrowsky ◽  
James Goff ◽  
Catherine Chagué ◽  
Douglas Stead ◽  
...  
Keyword(s):  
British Columbia ◽  
Numerical Models ◽  
Submarine Landslides ◽  
Tsunami Waves ◽  
Fractured Bedrock ◽  
The Pacific ◽  
Future Events ◽  
Threshold Volume ◽  
Resilient Infrastructure ◽  
Insight Into

AbstractRecurrent storms, floods, landslides, earthquakes and tsunamis challenge the development of resilient infrastructure and communities in coastal northwestern British Columbia. Vulnerability assessment first requires extended and improved understanding of geohazards in the Pacific Basin to constrain modelling of future events. An investigation of soils and bedrock structures in the Douglas Channel provides insight into the distribution of deposits attributed to geohazards in the region. Newly discovered marine inundation deposits corroborate numerical models and suggest that Pacific-sourced storms and earthquake-triggered tsunamis expend much of their energy in the outer coast and rarely reach far up the mainland fjords. Small-volume Folisolic slides and rockfalls do not generate tsunamis of any consequence. In contrast, marine sediments deposited beyond storm berms at the fjord head are a record of local tsunamis generated by large-volume marine slumps. Deep-fractured bedrock mapped upslope from relict submarine features would trigger damaging tsunami waves if rapid failure into the fjord were to occur. The observations above suggest only great earthquakes, large landslides and seasonal storms above a certain threshold volume and impulse energy produce geomorphically significant inundation events. However, even small submarine landslides have tsunamigenic potential in Douglas Channel since they occur in shallow water.

Numerical Model of the 1771 Meiwa tsunami and the influence of the reef

2020 ◽  
Author(s):  
Marine Le Gal ◽  
Satoshi Mitarai
Keyword(s):  
Water Depth ◽  
Pacific Islands ◽  
Reference Model ◽  
Numerical Models ◽  
Water Model ◽  
Shallow Water Model ◽  
Tsunami Waves ◽  
Ishigaki Island ◽  
Future Events ◽  
Tsunami Event

<p>In 1771, a major tsunami event hit the Yaeyama Islands (Japan) and particularly Ishigaki Island, where 30m run-ups were estimated. As with many other Pacific Islands, Ishigaki Island is surrounded by a reef. Interactions between tsunami waves and reefs have generally been analyzed with idealized models and studies focusing on a specific reef are rare. It has been shown that the influence of the reef is two-fold : it can either amplify or buffer waves. For the particular 1771 event, this influence is still unknown and the present study aims to identify it. Several numerical models were developed using the 2D Nonlinear Shallow Water model of the Telemac system. First, a reference model was build, simulating the real event with an accurate reef representation. Then, altered bathymetry models were generated and compared to the reference model. In our simulations, overall, the reef protected the coast with a 12,5% decrease of the water depth at the shoreline. However channels, disrupting the continuity of the reef, strongly amplified inundations on the nearby coast, with up to 40% increase of the water depth at the shoreline. To go further, this results could provide inside to better manage the coast for future events.</p>

scholarly journals SUBMARINE MASS FAILURE: WAVE GENERATION BY GRANULAR SLIDES

2018 ◽  
pp. 47
Author(s):  
Frederic M. Evers ◽  
Helge Fuchs ◽  
David Vetsch ◽  
Robert M. Boes
Keyword(s):  
Laboratory Experiments ◽  
Numerical Models ◽  
Experimental Studies ◽  
Wave Generation ◽  
Data Set ◽  
Ongoing Research ◽  
Tsunami Waves ◽  
Potential Source ◽  
Submarine Mass Failure ◽  
Insight Into

Submarine mass failures (SMF) are a potential source of hazardous tsunamis. While the link between seismic events and the magnitude of tsunami waves has been extensively studied and corresponding approaches are included in numerical tsunami warning models, the basic implementation of SMF generated waves is subject to ongoing research. In this context, laboratory experiments are essential for the validation of numerical schemes. Most experimental studies apply rigid slide models whereas only few include granular slides (e.g. Watts 1997, Ataie-Ashtiani & Najafi-Jilani 2008, Grilli et al. 2017). The objective of this study is to gain a better insight into the hydraulic processes related to wave generation by submarine granular slides based on experiments as well as establishing a comprehensive data set for the validation of numerical models.

scholarly journals Applicability of Calculation Formulae of Impact Force by Tsunami Driftage

2021 ◽  
Vol 9 (5) ◽  
pp. 493
Author(s):  
Yoshimichi Yamamoto ◽  
Yuji Kozono ◽  
Erick Mas ◽  
Fumiya Murase ◽  
Yoichi Nishioka ◽  
...  
Keyword(s):  
Large Scale ◽  
Impact Force ◽  
Numerical Models ◽  
Indian Ocean Tsunami ◽  
Tsunami Waves ◽  
Secondary Damage ◽  
The Pacific ◽  
American Society ◽  
The Impact ◽  
Civil Engineers

The aftermath of the Indian Ocean tsunami on 26 December 2004 triggered by the off Sumatra earthquake (magnitude “M” = 9.1), and the Great East Japan earthquake of 11 March 2011 off the Pacific coast of Tohoku (M = 9.0), evidence the secondary damage from driftage collision due to large tsunami waves. To prevent this type of damage, the establishment of methods for predicting driftage movement and calculating the impact force by driftage is necessary. Several numerical models have been developed to predict the driftage movement of objects. Every year, these improve in accuracy and usability. In contrast, there are many calculation formulae for calculating the impact force. However, since there are considerable differences between values calculated using these formulae, the reliability of each formula is unknown. Therefore, in this research, one team of the committee on tsunami research of the Japan Society of Civil Engineers summarizes the main calculation formulae of impact forces that have been proposed until 2019. In addition, for each type of driftage (driftwood, containers, cars, ships), we compare calculation values of these formulae with measured data of large-scale experiments. Finally, we check the range of calculation values for each formula up to 15 m/s in collision velocity and clarify then the following facts: (1) In the case of driftwood, the formulae of Matsutomi, Federal Emergency Management Agency (FEMA) and National Oceanic and Atmospheric Administration (NOAA), and American Society of Civil Engineers (ASCE) are most reliable; (2) In the case of containers, the formulae of Matsutomi, Arikawa et al., FEMA and NOAA, Ikeno et al., and ASCE are most reliable; (3) In the case of cars, the formulae of FEMA and NOAA, and ASCE are most reliable; (4) In the case of ships, the formulae of Mizutani, FEMA and NOAA, and ASCE are most reliable.

USE OF KNOTTED STRING ACCOUNTING RECORDS IN OLD HAWAII AND ANCIENT CHINA

1983 ◽  
Vol 10 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Lyle E. Jacobsen
Keyword(s):  
Writing Process ◽  
Ancient China ◽  
The Pacific ◽  
East And West ◽  
Insight Into

The use of the “quipu” for accounting purposes has been primarily attributed to the Peruvian Inca culture in the days of old. Documented evidence, however, provides that early Hawaiians and ancient Chinese predated the Incan usage. Studies concentrating on the quipu as an accounting device rather than as an element in the evolution of the writing process might provide valuable contributions to the solution of the mystery surrounding this artifact. Insight into the development of mankind in the Pacific may be gained by understanding the use of the quipu in the East and West, and in Hawaii—the “meeting place” of the Pacific.

Experiments on Oral Secretion of the Rocky Mountain Wood Tick, Dermacentor andersoni Stiles (Acarina: Ixodidae)

1957 ◽  
Vol 89 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. D. Gregson
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Rocky Mountain ◽  
Dermacentor Variabilis ◽  
Oral Secretion ◽  
Amblyomma Maculatum ◽  
Dermacentor Andersoni ◽  
The Pacific ◽  
Tick Paralysis ◽  
Rocky Mountain Wood Tick

Tick paralysis continues to be one of the most baffling and fascinating tickborne diseases in Canada. It was first reported in this country by Todd in 1912. Since then about 250 human cases, including 28 deaths, have been recorded from British Columbia. Outbreaks in cattle have affected up to 400 animals at a time, with losses in a herd as high as 65 head. Although the disease is most common in the Pacific northwest, where it is caused by the Rocky Mountain wood tick, Dermacentor andersoni Stiles, it has lately been reported as far south as Florida and has been produced by Dermacentor variabilis Say, Amblyomma maculatum Koch, and A. americanum (L.) (Gregson, 1953). The symptoms include a gradual ascending symmetrical flaccid paralysis. Apparently only man, sheep, cattle, dogs, and buffalo (one known instance) are susceptible, but even these may not necessarily be paralysed.

scholarly journals Intermittent but Rapid Changes to Coastal Landscapes: The Tsunami and El Niño Wave-Formed Sea Arch at Laie Point, Oahu, Hawaii, U.S.A.

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 147
Author(s):  
Benjamin R. Jordan
Keyword(s):  
El Niño ◽  
El Nino ◽  
Sand Dunes ◽  
Tsunami Source ◽  
Tsunami Waves ◽  
Storm Waves ◽  
The Pacific ◽  
Coastal Landscapes ◽  
Wave Heights ◽  
First Time

Kukuiho’olua Island is an islet that lies 164 m due north of Laie Point, a peninsula of cemented, coastal, Pleistocene and Holocene sand dunes. Kukuiho’olua Island consists of the same dune deposits as Laie Point and is cut by a sea arch, which, documented here for first time, may have formed during the 1 April 1946 “April Fools’s Day Tsunami.” The tsunami-source of formation is supported by previous modeling by other authors, which indicated that the geometry of overhanging sea cliffs can greatly strengthen and focus the force of tsunami waves. Additional changes occurred to the island and arch during the 2015–2016 El Niño event, which was one of the strongest on record. During the event, anomalous wave heights and reversed wind directions occurred across the Pacific. On the night of 24–25 February 2016, large storm waves, resulting from the unique El Niño conditions washed out a large boulder that had lain within the arch since its initial formation, significantly increasing the open area beneath the arch. Large waves also rose high enough for seawater to flow over the peninsula at Laie Point, causing significant erosion of its upper surface. These changes at Laie Point and Kukuio’olua Island serve as examples of long-term, intermittent change to a coastline—changes that, although infrequent, can occur quickly and dramatically, potentially making them geologic hazards.

scholarly journals Conservation Evaluation of the Pacific Population of Dwarf Woollyheads, Psilocarphus brevissimus var. brevissimus, in Canada

2006 ◽  
Vol 120 (2) ◽  
pp. 163
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny ◽  
Ksenia Barton
Keyword(s):  
British Columbia ◽  
Coalbed Methane ◽  
Groundwater Levels ◽  
Gas Drilling ◽  
Pacific Population ◽  
South Central ◽  
The Pacific ◽  
Recreational Vehicles ◽  
Forest Openings ◽  
Conservation Evaluation

In Canada, Dwarf Woolly-heads, Psilocarphus brevissimus var. brevissimus, is restricted to the Similkameen River valley, south of Princeton in southwestern British Columbia and the extreme southeast and southwest corners of Alberta and Saskatchewan, respectively. This paper deals with the three British Columbia populations which represent the northwestern limit of the species which ranges from south-central British Columbia, southward in the western United States to Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, California and Baja California, Mexico. In British Columbia, P. brevissimus is associated with calcareous vernal pools and ephemeral pond edges in large forest openings. This habitat is rare in the area the few existing populations could easily be extirpated or degraded through slight changes in groundwater levels, coalbed methane gas drilling, housing development or recreational vehicles.

Incentives for Using LEIM in the Investigation of Corrosion Initiation on Organic Coated Alloys

2001 ◽  
Vol 699 ◽  
Author(s):  
S. R. Taylor ◽  
A.M. Mierisch
Keyword(s):  
Electrochemical Impedance ◽  
Numerical Models ◽  
Physical Phenomenon ◽  
Product Formation ◽  
Coated Metal ◽  
Aqueous Environments ◽  
Damage Process ◽  
Experimental Process ◽  
Measurement Artifact ◽  
Insight Into

AbstractLocal electrochemical impedance mapping and spectroscopy (LEIM/S) have become important tools for the investigation of local electrochemical breakdown events associated with the degradation of organically coated metals in aqueous environments. LEIM/S of organic coated metal substrates has revealed local degradation events that are distributed spatially and temporally. These observations provide support to a number of long-standing theories, as well as provide new insight into the damage process. The local changes in impedance observed at early stages of immersion support the presence of virtual pores, while the metastability of impedance peaks representing the local changes provide evidence of healing via corrosion product formation. Each of these are long-standing theories used to explain global electrochemical impedance measurements. This paper will provide an overview of some of the events observed using LEIM and examine these results in the context of recent analytical and numerical models. Models used to predict the electric field above an equipotential disk electrode support the interpretation of most experimental LEI data as being representative of chemical and physical phenomenon and not a result of measurement artifact. However, certain features may be an artifact of the finite nature of the experimental process. The interpretation of LEIM events in view of current experimental and modeling results will be discussed.

Simulation of tsunami waves generated by submarine landslides in the Black Sea

2015 ◽  
Vol 30 (4) ◽  
Author(s):  
Gayaz S. Khakimzyanov ◽  
Oleg I. Gusev ◽  
Sofya A. Beizel ◽  
Leonid B. Chubarov ◽  
Nina Yu. Shokina
Keyword(s):  
Surface Waves ◽  
Black Sea ◽  
Numerical Technique ◽  
Submarine Landslide ◽  
The Black Sea ◽  
Submarine Landslides ◽  
Hydrodynamic Approximation ◽  
Tsunami Waves ◽  
Dispersive Model ◽  
Shallow Water Models

AbstractNumerical technique for studying surface waves appearing under the motion of a submarine landslide is discussed. This technique is based on the application of the model of a quasi-deformable landslide and two shallow water models, namely, the classic (dispersion free) one and the completely nonlinear dispersive model of the second hydrodynamic approximation. Numerical simulation of surface waves generated by a large model landslide on the continental slope of the Black Sea near the Russian coast is performed. It is shown that the dispersion has a significant impact on the picture of propagation of tsunami waves on sufficiently long paths.

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