• Periods of heightened volcanic seismicity across the Aleutian Arc, Alaska

      Christensen, Branden Carl (2010-08)
      "Data from the Alaska Volcano Observatory and Alaska Earthquake Information Center catalogs are applied to four research initiatives. In Chapter 1, the distinction between mainshock-aftershock sequences and swarms is made on the basis of how the total elastic energy is partitioned between the largest and smaller magnitude earthquakes. Chapter 2 establishes that multiplets are ubiquitous to periods of heightened volcano-seismicity across the Aleutian Islands and argues that they arise from the diffusion of heat and/ or pore fluids through the system and not from an increase in stress. The attributes of the 2008 Kasatochi eruption and pre-eruptive swarm are discussed in Chapter 3. Cross-correlation techniques are employed to root out additional waveforms that were either below the threshold of the detection or location algorithms used. The onset time of the pre-eruptive swarm is redefined and its temporal development more fully characterized. Chapter 4 integrates seismic and acoustic data to analyze the Continuous Phase of the 2006 eruption of Augustine Volcano. The Continuous Phase is shown to be a scaled-down version of the Explosive Phase. What was perceived by remote sensing observations as a continuous, unperturbed eruption is shown here to be a rapid succession of discrete blasts"--Leaf iii