@article {yarce_temporal_2023,
	title = {Temporal Relationship of Slow Slip Events and Microearthquake Seismicity: Insights From Earthquake Automatic Detections in the Northern Hikurangi Margin, Aotearoa New Zealand},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {24},
	number = {3},
	year = {2023},
	note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022GC010537},
	month = {03/2023},
	pages = {e2022GC010537},
	abstract = {Slow slip events in the northern Hikurangi margin of Aotearoa New Zealand occur every 18{\textendash}24 months and last for several weeks before returning to average convergence rates of around 38 mm/yr. Along this plate boundary, the Hikurangi plateau subducts beneath the overlying Australian plate and slow slip events occur along their plate interface at depths between 2 and 15 km. To explore whether there is a temporal relationship between slow slip events and earthquake occurrence, the Regressive ESTimator automated phase arrival detection and onset estimation algorithm was applied to a data set of continuous waveform data collected by both land and ocean bottom seismometers. This detector uses an autoregressive algorithm with iterative refinement to first detect seismic events and then create a catalog of hypocenters and P and S wave arrival times. Results are compared with an available catalog of manually detected seismic events. The auto-detector was able to find more than three times the number of events detected by analysts. With our newly assembled data set of automatically detected earthquakes, we were able to determine that there was an increase in the rate of earthquake occurrence during the 2014 slow slip event.},
	keywords = {earthquake detection, Hikurangi, ocean bottom seismometers, seismicity, slow slip event, subduction},
	issn = {1525-2027},
	doi = {10.1029/2022GC010537},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GC010537},
	author = {Yarce, Jefferson and Sheehan, Anne F. and Roecker, Steven}
}
@article {wang_temporal_2022,
	title = {Temporal velocity variations in the northern Hikurangi margin and the relation to slow slip},
	journal = {Earth and Planetary Science Letters},
	volume = {584},
	year = {2022},
	month = {04/2022},
	pages = {117443},
	abstract = {Slow slip events (SSE) have been studied in increasing detail over the last 20 years, improving our understanding of subduction zone processes. Although the relationship between SSEs and the physical properties of their surrounding materials is still not well-understood, the northern Hikurangi margin in New Zealand is the site of relatively shallow (<10 km deep), frequent SSEs, providing excellent opportunities for near-field investigations. From September to October 2014, an SSE occurred with more than 250 mm slip, and was recorded successfully by the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) deployment. This study applies scattered wave interferometry to ambient noise data acquired by nine HOBITSS ocean bottom seismometers (OBS) to study the seismic velocity variations related to the SSE. Single station cross-component correlations are computed within a period band that focuses on the upper plate in our study region. The average velocity variations display a decrease on the order of 0.05\% during the SSE, followed by an increase of similar magnitude afterwards. We suggest two possibilities. The first possibility, which has been suggested by other seismological observations, is that the SSE causes a low-permeability seal on the plate boundary to break. The break allows fluid to migrate into the upper plate, causing a seismic velocity decrease during the SSE because of increased pore fluid volume in the upper plate. Under this model, after the SSE, the fluids in the upper plate diffuse gradually and the velocity increases again. The second possibility is the velocity changes are related to changes in crustal strain during the slow slip cycle, whereby elastic strain accumulates prior to the SSE, causing contraction and reduction of porosity and therefore increase of velocity above the SSE source (the seismic velocity increases between SSEs). During the SSE the upper plate goes into extension as the elastic strain is released, which results in dilation and a porosity increase (seismic velocity reduction). After the SSE, stress and strain accumulate again, causing a porosity decrease and a velocity increase.},
	keywords = {ambient noise, seismic velocity variations, slow slip event, the Hikurangi subduction zone},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2022.117443},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X22000796},
	author = {Wang, Weiwei and Savage, Martha K. and Yates, Alexander and Zal, Hubert J. and Webb, Spahr and Boulton, Carolyn and Warren-Smith, Emily and Madley, Megan and Stern, Tim and Fry, Bill and Mochizuki, Kimihiro and Wallace, Laura}
}
