Retrieving "Seismometer" from the archives

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1. Earthquake

   Linked via "seismometer"

   | Richter Scale ($ML$) | Logarithmic measure of maximum trace amplitude on a seismogram calibrated for specific regional distances. | Small to moderate local earthquakes. | Poor; tends to saturate above $M6.5$. |
   | Moment Magnitude Scale ($Mw$) | Seismic Moment ($M0$)/), derived from the rigidity, area, and slip of the fault rupture. | All sizes, particularly large events. | High; considered the standard for scientific reporting. |
   | Durati…

2. San Andreas Fault System

   Linked via "seismometers"

   Deep Structure and Mantle Interaction
   The geometry of the SAFS at depth is complex. Seismic reflection data indicate that the main fault plane dips moderately $\left(\sim 60^\circ\right)$ in the upper crust but appears to flatten out into a near-horizontal geometry at depths between $15\ \text{km}$ and $25\ \text{km}$. This transition zone is critical, as it is hypothesized that the interaction between the friction of the grinding plates and the lower crust's in…

3. Tectonic Sighing

   Linked via "seismometers"

   Detection and Instrumentation
   Direct measurement of Tectonic Sighing is exceedingly difficult due to its extremely low frequency and the massive attenuation inherent in deep-Earth acoustics. Traditional seismometers are generally inadequate. Detection relies on hypersensitive instruments known as 'Barometric Resonance Nullifiers' (BRN arrays). These devices, often deployed in deep mine shafts or abandoned boreholes to minimize surface noise, measure minut…