I haven't looked for awhile, but there seems to be more recent papers that connect lunar gravitational triggering to earthquake activity:
* A Myth of Preferred Days of Strong Earthquakes?
Vladimir G. Kossobokov; Giuliano F. Panza
Seismological Research Letters (2020) 91 (2A): 948–955.
> "On the other hand, the same Kuiper test permits the rejection of the null hypotheses of the same chance of occurrence on any JD or MP for strong magnitude M≥6.0 earthquakes, at least for the past four decades of presumably the best‐earthquake determinations and, in particular, for earthquakes in the Northern Hemisphere (with an evident seasonal pattern). The nonparametric two‐sample Kolmogorov–Smirnov test statistics suggest no preferred distances to the Moon at the occurrence of large earthquakes. All of this contributes, to the results of solid statistical testing of hypotheses, for a better understanding of the complex seismic response of the Earth’s lithosphere to periodic gravitational loading."
Hough who [apparently is the head of the USGS office in Pasadena](https://en.wikipedia.org/wiki/Susan_Hough) gets challenged in this one:
> "Correlation of giant earthquakes with the lunar phase in seven Indo-Pacific
2 subduction zones and around Mongolia" => "The most important point of this research is that we divided the earthquakes by their locations. Hough (2018) carried out simple simulations and concluded that the occurrence of MW > 8 earthquakes ~1900 onward had nothing to do with lunar phases. However, her conclusion is inadequate since she analyzed all events at the same time **without considering their locations.** "
Wow, this is quite a smackdown. Why a geophysicist wouldn't consider that the distance from the moon to the earth varies in both time and geospatial location is perplexing. What do you think @DanielGeisler ?
And regarding seismology, this is an absolute killer study in how the long period lunar tropical tide **Mf** is strongly detectable at the bottom of the ocean
* Tidal Triggering of the Harmonic Noise in Ocean‐Bottom Seismometers Telluri Ramakrushana Reddy; Pawan Dewangan; Lalit Arya; Pabitra Singha; Kattoju Achuta Kamesh Raju Seismological Research Letters (2020) 91 (2A): 803–813. https://doi.org/10.1785/0220190080
> " It is likely that the HN observed in the present study is related to seafloor currents generated by tides."