TREM seismic network
TREM-net (the TREM seismic network) is the seismic network ExpTech built. ExpTech has been building it across Taiwan since 2022. Seismometers ExpTech designed record three-axis ground motion. Each station’s seismic intensity updates every second.
Each station connects to both core sites, Tainan and Tokyo, at the same time (dual uplink). Each site receives the data, computes, and syncs with the other. If one site stops, the other still produces real-time seismic intensity. For the data path and how redundancy works, see Architecture and geo-redundancy.
TREM data notice
TREM data are automated, real-time observations from ExpTech's own station network (TREM-net). They are not official earthquake information. In Taiwan, the authority on earthquake information is the Central Weather Administration (CWA) of the Ministry of Transportation and Communications, and information published by the CWA always prevails. In this notice, TREM data means TREM-net observations and detections. TREM EEW is provided only to specific users who have ExpTech's individual approval or a contract, and its use is governed by Article 4-1 of the Terms of Service.
When you use TREM data, you must:
- Defer to the CWA.Earthquake reports, earthquake early warnings, seismic intensity and tsunami information published by the CWA prevail. Where TREM data differ from official information, follow the official information.
- Label it as unofficial.Wherever you present TREM data, show the data source together with the statement "Unofficial information; the Central Weather Administration's releases prevail."
- Comply with the Meteorological Act.Under Article 17(1) of Taiwan's Meteorological Act, forecasts and warnings of earthquakes are issued exclusively by the central meteorological authority, and Article 18 does not allow other agencies, schools, organizations or individuals to issue earthquake forecasts or any warnings to the general public; providing them to specific users is not restricted. Violations are subject to a fine of NT$200,000 to NT$1,000,000 under Article 24(2), which may be imposed for each violation.
- Never use it unlawfully.Do not use TREM data to predict earthquakes or to issue earthquake or tsunami warnings, and do not spread unverified earthquake information. Spreading rumours or false information about disasters that harms the public or others is punishable under Article 53(3) of the Disaster Prevention and Protection Act by up to three years of imprisonment, detention, or a fine of up to NT$1,000,000. Spreading rumours that may disturb public peace is punishable under Article 63(1)(5) of the Social Order Maintenance Act by detention of up to three days or a fine of up to NT$30,000.
- Know its limits.TREM observations are automated and not reviewed by staff. Noise, device faults or network delays can cause false detections, missed events or delays. Never use them as the sole basis for evacuation, closures or any other safety decision.
The four subnets
Section titled “The four subnets”TREM-net is split into four subnets by sensor and precision. From lowest to highest precision, the order is SE-net < ES-net < HS-net < MS-net.
- Precision rank 1 of 4 subnets, counting from the lowestSE-netStrong Earthquake Networkstrong-motion networkMEMS accelerometer
- Precision rank 2 of 4 subnets, counting from the lowestES-netEnhanced Sensitivity Networkenhanced-sensitivity seismic networkMEMS accelerometerES-Net and ES-Pro belong to this subnet
- Precision rank 3 of 4 subnets, counting from the lowestHS-netHigh Sensitivity Networkhigh-sensitivity seismic networkMEMS accelerometer
- Precision rank 4 of 4 subnets, counting from the lowestMS-netMicro Seismographic Networkmicro-seismic networkelectromagnetic velocity sensor
- SE-net, ES-net, and HS-net use MEMS accelerometers. MS-net uses an electromagnetic velocity sensor.
- The ES-Net and ES-Pro seismometers are ES-net stations. ES-net went online in November 2025.
How the data is published
Section titled “How the data is published”TREM-net data is published over the SSE real-time stream. There are two topics:
trem.rts.v1(TREM station data): one snapshot of the whole network every 0.5 seconds. It includes each station’s continuous seismic intensity, peak acceleration, and whether the station is part of an earthquake.trem.intensity.v1(TREM intensity reports): during shaking, a list of the townships at each intensity level, from the intensity the stations actually measured (XML).
TREM-net data is Attribution · Non-commercial only. Credit the source when you use it, for example “Data: ExpTech Studio TREM (exptech.dev) · Non-commercial use · Unofficial information; the Central Weather Administration's releases prevail”, and use it for non-commercial purposes only. To use it commercially, request commercial use first. For where to put the credit and other examples, see Data license & attribution.
Join TREM-net
Section titled “Join TREM-net”Anyone can buy an ES series seismometer and set up a station at home to join TREM-net. After you mount the seismometer, connect it to Wi-Fi with ExpTech Home, and leave networked mode on (it is on by default), tell a station engineer on Discord. ExpTech watches data quality for 3–5 days. After confirming there is no problem, the station appears on the map and officially joins TREM-net.