Tracing The Movement And Storage Of Magma In The Crust Through Seismology: Examples From Alaska And Western Mexico

Thesis (Ph.D.) University of Alaska Fairbanks, 2010Four studies are presented that examine magma movement and storage in the crust using seismology at three different volcanoes: Fourpeaked volcano in the Cook Inlet region of Alaska, Paricutin volcano in the Michoacan-Guanajato volcanic field in western Mexico, and Colima volcano at the western edge of the Trans-Mexican Volcanic Belt. In 2006, Fourpeaked volcano, Alaska, had a widely-observed phreatic eruption. A modest seismic network was installed in stages following the unrest. The eruption was followed by several months of sustained seismicity punctuated by vigorous swarms and SO2 emissions exceeding a thousand tons/day. Based on the history of Fourpeaked, and observations during and after the phreatic eruption, it is proposed that the activity was caused by a modest injection of new magma beneath the volcano. Also presented are a series of studies from western Mexico, an area of high seismic and volcanic activity. A description of the creation of an automatically generated regional catalog of seismic activity is presented, along with a comparison with existing seismicity studies of the area. From this catalog, a swarm of earthquakes near Parfcutin in May-June 2006 was discovered. This swarm demonstrated a steady upward migration in depth with time. Focal mechanisms during the first part of the swarm reflect the increased stress caused by dike inflation. In early June, the stress orientation changed and became more consistent with the inflation of a horizontal sill-like structure. At Colima volcano, a P-wave tomographic inversion using arrivals from 299 regional earthquakes is presented. The results of the inversion show two distinct low-velocity zones. One is in the upper 10 km under the volcano and may be caused by a magma chamber-type structure. The second anomaly, with peak values of 2.5% slower velocities, was imaged in the crust southeast of the volcano at depths of 15-30 km. This body may be due to partial melt and increased temperatures from a second, deeper area of magma storage

Corn Residue Grazing as a Component of Semi-Confined Cow-Calf Production and the Effects of Post-weaning Management on Feedlot Performance

Grazing corn residue can be a valuable alternative to harvested winter feed in a cow-calf production enterprise. The objectives of the first study were to: 1) determine the sample size needed to accurately estimate yield of corn grain and residue and 2) evaluate changes in residue quality throughout the fall/winter and spring-grazing seasons. Results suggest that 6-10 plants serve as a representative sample for grain yield while 7- 10 plants are needed for a representative sample of residue yield. In vitro OM digestibility was greatest at the beginning of the fall and spring grazing seasons and declined over time (P \u3c 0.01). In vitro OM digestibility of available residue declined 21% over the fall-grazing season and 51% throughout the spring-grazing season. A second study evaluated the effects of 2 winter cow-calf production systems on cow-calf performance at 2 locations. Cows wintered on cornstalks at ENREC lost BW and had a 0.46 unit decrease in BCS, while cows in the dry-lot gained BW and had a 0.24 unit increase in BCS (P \u3c 0.01). At PREC, BCS increased by 0.03 units for cows wintered in the dry-lot and decreased by 0.26 units for cows wintered on cornstalks (P = 0.04). At ! both locations, calves wintered in the dry-lot had greater ADG and BW per d of age compared to calves wintered on cornstalks (P ≤ 0.03). A partial budget suggests that lower winter production inputs may be significant enough to compensate for reduced performance of calves when cow-calf pairs are wintered on cornstalks. A third experiment evaluated the effects of winter cow-calf production system and post-weaning management on finishing performance and carcass characteristics of calves sourced from experiment two. Calves that had previously been winter grazed on cornstalks had lighter initial BW entering the finishing phase than calves wintered in the dry-lot (P \u3c 0.01). Calves directly adapted to a finishing diet following weaning had greater finishing ADG (P \u3c 0.01) and improved G:F (P \u3c 0.01). Calves that were fed a growing diet prior to the finishing phase produced 35 kg greater final BW (P \u3c 0.01) and 23 kg greater carcass weight (P \u3c 0.01). Directly finishing calves resulted in greater net profit compared to growing calves prior to the finishing phase (P \u3c 0.01) as the extra carcass weight did not offset the cost of the additional 49 days in the feedlot. Advisor: Andrea K. Watso

Pollination by flies, bees, and beetles of Nuphar ozarkana and N. advena (Nymphaeaceae)

Nuphar comprises 13 species of aquatic perennials distributed in the temperate Northern Hemisphere. The European species N. lutea and N. pumila in Norway, the Netherlands, and Germany are pollinated by bees and flies, including apparent Nuphar specialists. This contrasts with reports of predominant beetle pollination in American N. advena and N. polysepala. We studied pollination in N. ozarkana in Missouri and N. advena in Texas to assess whether (1) there is evidence of pollinator shifts associated with floral-morphological differences between Old World and New World species as hypothesized by Padgett, Les, and Crow (American Journal of Botany 86: 1316–1324. 1999) and (2) whether beetle pollination characterizes American species of Nuphar. Ninety-seven and 67% of flower visits in the two species were by sweat bees, especially Lasioglossum (Evylaeus) nelumbonis. Syrphid fly species visiting both species were Paragus sp., Chalcosyrphus metallicus, and Toxomerus geminatus. The long-horned leaf beetle Donacia piscatrix was common on leaves and stems of N. ozarkana but rarely visited flowers. Fifteen percent of visits to N. advena flowers were by D. piscatrix and D. texana. The beetles’ role as pollinators was investigated experimentally by placing floating mesh cages that excluded flies and bees over N. advena buds about to open and adding beetles. Beetles visited 40% of the flowers in cages, and flowers that received visits had 69% seed set, likely due to beetle-mediated geitonogamy of 1st-d flowers. Experimentally outcrossed 1st-d flowers had 62% seed set, and open-pollinated flowers 76%; 2nd-d selfed or outcrossed flowers had low seed sets (9 and 12%, respectively). Flowers are strongly protogynous and do not self spontaneously. Flowers shielded from pollinators set no seeds. A comparison of pollinator spectra in the two Old World and three New World Nuphar species studied so far suggests that the relative contribution of flies, bees, and beetles to pollen transfer in any one population depends more on these insects’ relative abundances (and in the case of Donacia, presence) and alternative food sources than on stamen length differences between Old World and New World pond-lilies

PEDESTRIAN TRAVEL-TIME MAPS FOR KODIAK, ALASKA: An anisotropic model to support tsunami evacuation planning

Tsunami-induced pedestrian evacuation for the City of Kodiak, U.S. Coast Guard Base and the community of Womens Bay is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points from the tsunami hazard zone. The pedestrian travel is restricted to the roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards.Tsunami-induced pedestrian evacuation for the City of Kodiak, U.S. Coast Guard Base and the community of Womens Bay is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points from the tsunami hazard zone. The pedestrian travel is restricted to the roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards

PEDESTRIAN TRAVEL-TIME MAPS FOR PERRYVILLE, ALASKA: An anisotropic model to support tsunami evacuation planning

Tsunami-induced pedestrian evacuation for the community of Perryville is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points located at the tsunami hazard zone boundary. Pedestrian travel-time maps are computed for two cases: i) travel to an existing evacuating shelter and ii) travel to either the evacuation or an alternative shelter. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards

PEDESTRIAN TRAVEL-TIME MAPS FOR WHITTIER, ALASKA: An anisotropic model to support tsunami evacuation planning

Tsunami-induced pedestrian evacuation for the community of Whittier is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points from the tsunami hazard zone boundary. The pedestrian travel is restricted to the roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards

2021 Alaska Seismicity Summary

The Alaska Earthquake Center reported 49,120 seismic events in Alaska and neighboring regions in 2021. The largest earthquake was a magnitude 8.2 event that occurred on July 29 southwest of Kodiak Island. It was followed by about 1,300 aftershocks including two magnitude 6.9 events on August 14 and October 11. Other active spots include sequences near Harding Lake in Interior Alaska in July-September and near Yakutat Bay in September. The largest earthquake in mainland Alaska was the M6.1 Chickaloon Earthquake on May 31. We continued to monitor ongoing activity within the 2018 M7.1 Anchorage, 2018 M6.4 Kaktovik, and 2018 M7.9 Offshore Kodiak aftershock sequences, the Purcell Mountains earthquake swarm, and the Wright Glacier cluster northeast of Juneau.1. Abstract 2. Introduction 3. Notable earthquakes and sequences of 2021 3.1. January 3 and September 24 M6.1 earthquakes in Andreanof Islands 3.2. May 31 M6.1 Chickaloon Earthquake 3.3. July 29 M8.2 Chignik Earthquake 3.4. July 23 M4.7 and September 14 M4.9 Harding Lake earthquakes 3.5. September 5-6 M4.0 and M4.1 Yakutat earthquakes 4. Ongoing aftershock sequences and swarms 4.1. 2020 M7.8 Simeonof aftershock sequence 4.2. 2018 M7.1 Anchorage aftershock sequence 4.3. 2018 M6.4 Kaktovik aftershock sequence 4.4. 2018 M7.9 Offshore Kodiak aftershock sequence 4.5. Purcell Mountains earthquake swarm 4.6. Northeast Brooks Range earthquake swarm 5. Glacial seismicity and Wright Glacier cluster 6. Acknowledgments 7. Reference

Maritime Guidance for Distant and Local Source Tsunami Events: Valdez Harbor, Alaska

These documents provide response guidance for Valdez Harbor in the event of tsunamis for small vessels such as recreational sailing and motor vessels, and commercial fishing vessels. The developed documents follow the guidance developed by the National Tsunami Hazard Mitigation Program (NTHMP) and are based on anticipated effects of a maximum-considered distant and locally generated tsunami event

Maritime Guidance for Distant and Local Source Tsunami Events: Sitka, Alaska

These documents provide response guidance for Sitka in the event of tsunamis for small vessels such as recreational sailing and motor vessels, and commercial fishing vessels. The developed documents follow the guidance developed by the National Tsunami Hazard Mitigation Program (NTHMP) and are based on anticipated effects of a maximum-considered distant and locally generated tsunami event

Maritime Guidance for Distant and Local Source Tsunami Events: Cordova Harbor, Alaska

These documents provide response guidance for Cordova Harbor in the event of tsunamis for small vessels such as recreational sailing and motor vessels, and commercial fishing vessels. The developed documents follow the guidance developed by the National Tsunami Hazard Mitigation Program (NTHMP) and are based on anticipated effects of a maximum-considered distant and locally generated tsunami event