@article {iwasaki_continuous_2022,
	title = {Continuous Tremor Activity With Stable Polarization Direction Following the 2014 Large Slow Slip Event in the Hikurangi Subduction Margin Offshore New Zealand},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {127},
	number = {2},
	year = {2022},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2021JB022161},
	month = {11/2021},
	pages = {e2021JB022161},
	abstract = {Many types of slow earthquakes have been discovered at subduction zones around the world. However, the physical process of these slow earthquakes is not well understood. To monitor offshore slow earthquakes, a marine seismic and geodetic experiment was conducted at the Hikurangi subduction margin from May 2014 to June 2015. During this experiment, a large slow slip event (Mw 6.8) occurred directly beneath the ocean bottom seismometer (OBS) network. In this study, S-wave splitting and polarization analysis methods, which have been previously used on onshore data to investigate tremor and anisotropy, are applied to continuous OBS waveform data to identify tremors that are too small to detect by the envelope cross correlation method. Continuous tremor activity with stable polarization directions is detected at the end of the 2014 slow slip event and continued for about 2 weeks. The tremors are generated around a southwest bend in the slow slip contours and at the landward edge of a subducted seamount. Our findings corroborate a previous interpretation, based on burst-type repeating earthquakes and intermittent tremor, that localized slow slip and tremor around the seamount was triggered by fluid migration following the large plate boundary slow slip event and indicate tremor occurred continuously rather than as isolated and sporadic individual events.},
	keywords = {New Zealand, polarization, S-wave splitting, Seamount, slow slip, tremor},
	issn = {2169-9356},
	doi = {10.1029/2021JB022161},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022161},
	author = {Iwasaki, Yuriko and Mochizuki, Kimihiro and Ishise, Motoko and Todd, Erin K. and Schwartz, Susan Y. and Zal, Hubert and Savage, Martha K. and Henrys, Stuart and Sheehan, Anne F. and Ito, Yoshihiro and Wallace, Laura M. and Webb, Spahr C. and Yamada, Tomoaki and Shinohara, Masanao}
}
@article {li_connections_2018,
	title = {Connections between subducted sediment, pore-fluid pressure, and earthquake behavior along the Alaska megathrust},
	journal = {Geology},
	volume = {46},
	number = {4},
	year = {2018},
	month = {02/2018},
	pages = {299{\textendash}302},
	abstract = {Variations in pore-fluid pressure along subduction megathrusts are often invoked to explain differences in fault slip behavior between margins. However, many other parameters vary between subduction zones, making it difficult to isolate the causes of elevated pore fluid pressures and their effects on megathrust behavior. Here we show evidence from pre-stack depth migrations of multichannel seismic reflection data along the subduction zone off the Alaska Peninsula for significant, systematic along-strike variations in the thickness, continuity, P-wave velocity, and estimated pore-fluid pressure of the subducting sediment layer that lines the shallow plate interface within 25 km of the trench. These variations appear to correlate with changes in seismicity, locking, and earthquake rupture history. The currently locked and seismically quiet Semidi segment has a continuous, thick (600{\textendash}900 m) subducted sediment layer that is characterized by low seismic velocities and elevated pore pressure (λ* ≈ 0.4{\textendash}0.8). The subducted sediment in the neighboring Shumagin Gap, a region with low geodetic coupling and abundant small earthquakes, is thinner, irregular and has lower pore pressure (λ* \&lt; 0.2{\textendash}0.3). We suggest that the thicker and weakly faulted sediment layer entering the trench at Semidi is associated with a continuous and overpressured sediment layer lining the shallow plate interface, but forms a large coherent asperity as it dewaters and consolidates at greater depths, thus favoring large earthquakes. In contrast, thinner incoming sediment disrupted by outer rise faulting at Shumagin results in a plate interface without elevated pore-fluid pressures, but which is heterogeneous and complex at all depths, contributing to creep and frequent small earthquakes.},
	issn = {0091-7613},
	doi = {10.1130/G39557.1},
	url = {https://doi.org/10.1130/G39557.1},
	author = {Li, Jiyao and Shillington, Donna J. and Saffer, Demian M. and B{\'e}cel, Anne and Nedimovi{\'c}, Mladen R. and Kuehn, Harold and Webb, Spahr C. and Keranen, Katie M. and Abers, Geoffrey A.}
}
