scholarly journals Magnetic Properties of Quaternary Deposits, Kenai Peninsula, Alaska -- Implications for Aeromagnetic Anomalies of Upper Cook Inlet

2004 ◽  
Author(s):  
R.W. Saltus ◽  
Peter J. Haeussler
Keyword(s):  
Magnetic Properties ◽  
Cook Inlet ◽  
Quaternary Deposits ◽  
Kenai Peninsula ◽  
Aeromagnetic Anomalies

scholarly journals Numerical simulation of tsunami generation by cold volcanic mass flows at Augustine Volcano, Alaska

2006 ◽  
Vol 6 (5) ◽  
pp. 671-685 ◽  
Author(s):  
C. F. Waythomas ◽  
P. Watts ◽  
J. S. Walder
Keyword(s):  
Numerical Simulation ◽  
North Pacific Ocean ◽  
Debris Avalanche ◽  
Pyroclastic Flows ◽  
Tsunami Generation ◽  
Cook Inlet ◽  
Kenai Peninsula ◽  
Debris Avalanches ◽  
Short Period ◽  
Mass Flows

Abstract. Many of the world's active volcanoes are situated on or near coastlines. During eruptions, diverse geophysical mass flows, including pyroclastic flows, debris avalanches, and lahars, can deliver large volumes of unconsolidated debris to the ocean in a short period of time and thereby generate tsunamis. Deposits of both hot and cold volcanic mass flows produced by eruptions of Aleutian arc volcanoes are exposed at many locations along the coastlines of the Bering Sea, North Pacific Ocean, and Cook Inlet, indicating that the flows entered the sea and in some cases may have initiated tsunamis. We evaluate the process of tsunami generation by cold granular subaerial volcanic mass flows using examples from Augustine Volcano in southern Cook Inlet. Augustine Volcano is the most historically active volcano in the Cook Inlet region, and future eruptions, should they lead to debris-avalanche formation and tsunami generation, could be hazardous to some coastal areas. Geological investigations at Augustine Volcano suggest that as many as 12–14 debris avalanches have reached the sea in the last 2000 years, and a debris avalanche emplaced during an A.D. 1883 eruption may have initiated a tsunami that was observed about 80 km east of the volcano at the village of English Bay (Nanwalek) on the coast of the southern Kenai Peninsula. Numerical simulation of mass-flow motion, tsunami generation, propagation, and inundation for Augustine Volcano indicate only modest wave generation by volcanic mass flows and localized wave effects. However, for east-directed mass flows entering Cook Inlet, tsunamis are capable of reaching the more populated coastlines of the southwestern Kenai Peninsula, where maximum water amplitudes of several meters are possible.

scholarly journals A Decade in Review: Alaska’s Adaptive Management of an Invasive Apex Predator

Fishes ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 12
Author(s):  
Kristine Dunker ◽  
Robert Massengill ◽  
Parker Bradley ◽  
Cody Jacobson ◽  
Nicole Swenson ◽  
...  
Keyword(s):  
Adaptive Management ◽  
Northern Pike ◽  
Fish Populations ◽  
Native Fish ◽  
Apex Predator ◽  
Cook Inlet ◽  
Kenai Peninsula ◽  
Control Actions ◽  
Southcentral Alaska ◽  
Population Suppression

Northern pike are an invasive species in southcentral Alaska and have caused the decline and extirpation of salmonids and other native fish populations across the region. Over the last decade, adaptive management of invasive pike populations has included population suppression, eradication, outreach, angler engagement, and research to mitigate damages from pike where feasible. Pike suppression efforts have been focused in open drainages of the northern and western Cook Inlet areas, and eradication efforts have been primarily focused on the Kenai Peninsula and the municipality of Anchorage. Between 2010 and 2020, almost 40,000 pike were removed from southcentral Alaska waters as a result of suppression programs, and pike have been successfully eradicated from over 20 lakes and creeks from the Kenai Peninsula and Anchorage, nearly completing total eradication of pike from known distributions in those areas. Northern pike control actions are tailored to the unique conditions of waters prioritized for their management, and all efforts support the goal of preventing further spread of this invasive aquatic apex predator to vulnerable waters.

Revised chronostratigraphy of the Kenai Group from 40Ar/39Ar dating of low-potassium bearing minerals, Cook Inlet Basin, Alaska

2004 ◽  
Vol 41 (10) ◽  
pp. 1159-1179 ◽  
Author(s):  
Todd A Dallegge ◽  
Paul W Layer
Keyword(s):  
Structural Deformation ◽  
Core Material ◽  
Cook Inlet ◽  
Kenai Peninsula ◽  
Late Tertiary ◽  
Low Potassium ◽  
Tephra Beds ◽  
Cook Inlet Basin ◽  
Low K ◽  
Stratigraphic Succession

Thirty-seven tephra beds, primarily from coal partings in the Sterling and Beluga formations, were successfully dated by the 40Ar/39Ar method providing a new and revised understanding of the chronostratigraphy of late Tertiary strata within Cook Inlet Basin. Meticulous sample preparation, multiple analyses, and statistical evaluation of the data were required for these low-K, plagioclase- and hornblende-bearing tephras. Dating of subsurface core material provides the first subsurface-to-outcrop tie in Cook Inlet between well 212-24 in the Beluga River Unit and deposits in the Clam Gulch, Diamond Creek, and Fox Creek areas. The new 40Ar/39Ar chronostratigraphic framework place the age of upper part of the Kenai Group strata between 4.6 and 9.4 Ma and support the 8-Ma interpretation of the boundary between the Homerian and Clamgulchian paleobotanical stages. The 49-Ma age from core data in Pioneer Unit suggests the Tyonek Formation is older than previously thought or that these units belong to an older formation. The chronostratigraphic framework demonstrates significant offset on faults along the Kenai Peninsula, the presence of faults in slumps and vegetated areas, disconformities in the stratigraphic succession, and that parts of the Sterling and Beluga formations are time-equivalent strata representing lateral facies variations. Based on crosscutting relations and structural folding, the established chronohorizons indicate that much of the structural deformation in Cook Inlet is no older than early Pliocene in age. The repeated section, due to faulting and the coeval nature of the formations, could significantly affect previous resource assessments of coal and hydrocarbon distributions.

scholarly journals Sedimentation conditions and rock-magnetic properties of Quaternary deposits from Laguna de Santa Rosa, Iturbide region, northeastern Mexico

2003 ◽  
Vol 42 (1) ◽  
pp. 25-39
Author(s):  
J Urrutia-Fucugauchi ◽  
M A Ruiz-Martínez ◽  
J Werner ◽  
H W Hubberten ◽  
T Adatte ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Quaternary Deposits ◽  
Sierra Madre Oriental ◽  
Rock Magnetic Properties ◽  
Sierra Madre ◽  
Northeastern Mexico ◽  
Factor Variable ◽  
Sedimentation Conditions

Se reportan resultados iniciales del estudio interdisciplinario de la secuencia lacustre de Laguna Santa Rosa, en el núcleo de 26 m de longitud recuperado en el sector norte-centro. Santa Rosa es una cuenca intermontaña, con una reducida zona de captación, altitud de 1520 m snm, y situada en el sector central de la Sierra Madre Oriental en la región de Iturbide en el noreste de México. Las variaciones estratigráficas de las propiedades magnéticas, contenido total de carbonato y carbón isotópico y mineralógico, definen tres zonas separadas por incrementos del cociente de calcita a quarzo+phyllosilicatos+feldespatos. La zona más somera, desde la superficie hasta 7-9 m, está formada por arcilla orgánica con abundancia de gasterópodos y dos arcillas de color negro a verde. Se caracteriza por susceptibilidad magnética alrededor de SI, factor de frecuencia de 0 %, 13 C que abarca desde -20.3 % a -26.4 %, presencia de cuarzo y phylosilicatos casi siempre con más de 20 % de calcita y esporádica aparición de plagioclasa (albita) y escaso contenido de K-feldespatos. La zona media, desde 9 m hasta 17.5 m, está formada por cinco unidades de arcilla que varían desde el verde grisáceo al café. Esta zona se caracteriza por su susceptibilidad variable arriba de 17 SI, factores de frecuencia negativos, bajo contenido total de carbonato, enriquecimiento de cuarzo y phylosilicatos, menos calcita y presencia de k-feldespatos. Esta zona media muestra un incremento en el aporte de detritos y/o productividad reducida, lo que sugiere un intervalo frío y menos húmedo. La zona más baja se extiende desde 17.5 m hasta 26 m y muestra dos unidades de arcilla que van del café al verde grisáceo. Esta zona se caracteriza por susceptibilidad magnética entre 8 10-6 SI y 14 SI, factor variable de frecuencia, y valores 13 C de alrededor -24 %. Su mineralogía es similar a la de la zona más somera, también rica en calcita y aparición de plagioclasa. La porción de phylosilicatos está compuesta principalmente de micas, clorita, esmectita y kaolinita. Los minerales magnéticos son alogénicos, derivados de lutitas y carbonatos que forman la cuenca de la zona de captación.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

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