@article {RN66,
	title = {Axial Seamount: Periodic tidal loading reveals stress dependence of the earthquake size distribution (b value)},
	journal = {Earth and Planetary Science Letters},
	volume = {512},
	year = {2019},
	pages = {39-45},
	type = {Journal Article},
	abstract = {Earthquake size-frequency distributions commonly follow a power law, with the b value often used to quantify the relative proportion of small and large events. Laboratory experi13 ments have found that the b value of microfractures decreases with increasing stress. Stud14 ies have inferred that this relationship also holds for earthquakes based on observations of earthquake b values varying systematically with faulting style, depth, and for subduction zone earthquakes, plate age. However, these studies are limited by small sample sizes de17 spite aggregating events over large regions, which precludes the ability to control for other variables that might also affect earthquake b values such as rock heterogeneity and fault roughness. Our natural experiment in a unique seafloor laboratory on Axial Seamount involves analyzing the size-frequency distribution of \~{}60,000 microearthquakes which
delineate a ring-fault system in a 25 km3 21 block of crust that experiences periodic tidal loading of {\textpm}20 kPa. We find that above a threshold stress amplitude, b value is inversely correlated with tidal stress. The earthquake b value varies by \~{}0.09 per kPa change in Coulomb stress. Our results support the potential use of b values to estimate small stress variations in the Earth{\textquoteright}s crust.},
	issn = {0012-821X},
	doi = {10.1016/j.epsl.2019.01.047},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X19300731},
	author = {Tan, Yen Joe and Waldhauser, Felix and Tolstoy, Maya and Wilcock, William S. D.}
}
@article {RN217,
	title = {The mechanism of tidal triggering of earthquakes at mid-ocean ridges},
	journal = {Nature Communications},
	volume = {10},
	number = {1},
	year = {2019},
	pages = {2526},
	type = {Journal Article},
	abstract = {The strong tidal triggering of mid-ocean ridge earthquakes has remained unexplained because the earthquakes occur preferentially during low tide, when normal faulting earthquakes should be inhibited. Using Axial Volcano on the Juan de Fuca ridge as an example, we show that the axial magma chamber inflates/deflates in response to tidal stresses, producing Coulomb stresses on the faults that are opposite in sign to those produced by the tides. When the magma chamber{\textquoteright}s bulk modulus is sufficiently low, the phase of tidal triggering is inverted. We find that the stress dependence of seismicity rate conforms to triggering theory over the entire tidal stress range. There is no triggering stress threshold and stress shadowing is just a continuous function of stress decrease. We find the viscous friction parameter A to be an order of magnitude smaller than laboratory measurements. The high tidal sensitivity at Axial Volcano results from the shallow earthquake depths.},
	issn = {2041-1723},
	doi = {10.1038/s41467-019-10605-2},
	url = {https://doi.org/10.1038/s41467-019-10605-2},
	author = {Scholz, Christopher H. and Tan, Yen Joe and Albino, Fabien}
}
