For #SeismogramSaturday #SeismoTwitter I thought it would be interesting to talk about a lesser known seismic phenomenon called “slow-rupture tsunami earthquakes, or simply “tsunami earthquakes”. There’s been some great info about the M 7.5 Ecuador earthquake a couple days ago, and this topic will discuss frequency content of earthquakes. Notably why earthquakes with the same magnitude may be very different from one another.

A summary of seismicity of New Zealand for 2018. There were no major earthquakes with extensive aftershock sequences in 2018, e.g. 2016 Kaikōura, and @GeoNet located 19 515 earthquakes in New Zealand and the adjacent offshore region. The pattern of shallow earthquakes (depth < 33 km) is typical, with much of the country susceptible to regular shallow seismicity, with lower rates in Northland/Auckland and southeast Otago.