★ N.I.C. ★
Design-stage concept — nothing built. The figures are verified against the parts' sheets and the parts before a node is made.
Quake is the station's seismograph: NodBus type 5, a NOD. A sealed tube seated in a hole in rock or soil, left alone for years. It measures ground acceleration on two accelerometers at different ranges, rotation on a gyro, tilt and drift on an inclinometer, and — by population — the magnetic field and the temperature of the ground at depth. 128 samples a second, 40 B a frame, levelled on the node.
MEMS, not geophones. A MEMS proof mass resonates in the kHz range, far above the seismic band below 20 Hz; the part is sealed on one die, calibrated at the factory, digital, three axes in one package — one chip where a geophone build takes three coils.
A strong-motion and local-event instrument, not an observatory seismometer. The MEMS noise floor — ~25 µg/√Hz on the precise part — sits well above a geophone's, so one node catches:
- felt local quakes, roughly M ≥ 3 within ~50 km;
- larger regional events, roughly M ≥ 4,5 out to a few hundred km;
- not the small distant event a geophone would — an M3 at 150 km is under the floor.
The network is the instrument: many nodes on a dense grid recover what one cannot, and the shared hardware clock aligns them to ±1 µs where a hobby seismograph on NTP holds ±10 ms — which is what makes arrival-time and cross-node work possible.
Every Quake is alone on its own Bifrost spur — point-to-point, full duplex, the unit end of the run. The node carries no line part: a power board for its feed and a communication board for its medium sit in the tube at the cable end, and the run — copper or glass, 48 V or 300 V — changes nothing on the Quake's own board. The clock is Kronos's, carried on the spur's clock pair; the node locks to it, clocks its sensors from it, and fires its frame in its slot. Installed at any angle within ~10° of vertical: one calibration command and the node levels itself from the gravity vector.
a Bifrost spur ══ the feed + the data pairs ══▶ power board + communication board ──┐
│ NB IN · PWR IN · 12V
┌──────────────────────────────┴──────┐
│ QUAKE — H523, type 5, 40 B a frame │
│ ADXL355 · ICM-42688-P · SCL3300 │
│ RM3100 and TMP117 by population │
│ an NTC between the coils │
└─────────────────────────────────────┘
Where the grid pays off — the priority belts and cities, from the siting rules in
../gaia/SITING.md; the layer is../gaia/priority-earthquake.geojson.
| file | contents |
|---|---|
HARDWARE.md |
the board — sensors, supply, the processor's pins, timers and clock tree, the bodies, the parts |
FIRMWARE.md |
the firmware, described — boot, the bus, time, acquisition, calibration, registers, faults |
BUS.md |
the payload, the 16-bit wire format, the report frame, storage |
CONSTRUCTION.md |
the seat in the ground, the Barrel family and its bending modes, depth, the cable |
WHY.md |
the graveyard — rejected alternatives and superseded states |
Hardware: CERN-OHL-S v2 (../LICENSE-HW) · Software: MIT (../LICENSE) — Copyright (c) 2026 NIC — Native Intellect Community