Seismometers

Last modified by robert on 2025/03/25 09:14

Broadband sensors

Broadband (or BB) sensors are especially sensitive to low-frequency energy and are broadly defined as any instrument capable of reliably recording wave periods greater or equal to 10 seconds. This makes them useful for the analysis and detection of teleseismic earthquakes as well as techniques involving ambient noise. However, they are also well-suited for measuring high-frequency energy, limited only by the Nyquist frequency of the data logger's sampling rate. The downside to broadband sensors is usually their cost, size, and fragility relative to short-period sensors.

Nanometrics

Currently, 4 kinds of nanometric broadband seismic sensors are available. The Trillium Compact 120, Trillium Compact 20, Trillium Compact Posthole, and most recently, the Trillium Compact Horizon. These seismometers are ideal for long-term deployments of multiple months. All of these seismometers are compatible with the LPR-200 and TSAWR loggers and are designed for low energy consumption.

Trillium Compact 120

The Trillium Compact 120 has sensitivity band between 120 seconds and 100 Hz but is prone to corrosion when buried for long periods. They have a tilt tolerance of ~10° but come with adjustable feet for leveling.

 For more information, refer to the Nanometrics instrument information sheet: https://nanometrics.ca/hubfs/Downloads/Data%20Sheets/trillium_compact.pdf?hsLang=en-ca

Trillium Compact 20

The Trillium compact has a recording range between 20 seconds and 100 Hz. but is prone to corrosion when buried for long periods. They have a tilt tolerance of ~10° but come with adjustable feet for leveling.

For more information, refer to the Nanometrics instrument information sheet: https://nanometrics.ca/hubfs/Downloads/Data%20Sheets/trillium_compact.pdf?hsLang=en-ca

Trillium Compact Posthole

The Trillium Compact Posthole is designed with a robust casing allowing it to be deployed via direct-burial without a vault or protective case. It does NOT have leveling feet nor a bubble (bring your own!), nor can its mass be rebalanced. The cable is also quite a bit more stiff so may require burial at an increased depth. If installed inside a vault, the cable may also unbalance the sensor if left by itself. The instrument response is identical to a Trillium Compact 120.

For more information, refer to the Nanometrics instrument information sheet:  https://nanometrics.ca/hubfs/Downloads/Data%20Sheets/trillium_compact_ph.pdf?hsLang=en-ca 

Trillium Compact Horizon

The Trillium Compact Horizon is sort of a mix between the Posthole and Compact 120, ideal for shallow direct bury deployments or instances where packing weight and size is an important consideration. Its response and sensitivity is identical to the Trillium Compact 120.

SmartSolo Broadbands

Two types of SmartSolo brand seismometers are currently available, one of which is a broadband seismometer. More information is available on the SmartSolo Seismometers page.

Short period sensors

Short-period (SP) sensors have limited sensitivity to longer periods, but are otherwise perfectly suitable for earthquake or other high-frequency analysis. They are generally defined as any instrument that begins to lose sensitivity at periods larger than 10 seconds. They tend to be smaller and more mechanically robust to broadband sensors.

Lennartz Electronic LE-3D Lite (MkII)

The LE-3D Lites are small, robust, short period sensors with a a corner period of 1 second.

SmartSolo Short periods

Two types of SmartSolo brand seismometers are currently available, one of which is a short-period seismometer with corner frequency of 5 Hz. More information is available on the SmartSolo Seismometers page.

Channel and Instrument conventions

We follow FDSN guidelines for sensor channel and type naming conventions, outlined at SAGE / IRIS

Trillium Compact 120

Trillium compact120.jpg

Frequency Band120 seconds to 100 Hz 
Sensitivity 754 V/m/s
Size (Diameter x Height)9 x 13 cm
Weight1.1 kg

Trillium Compact PostHole 120

Trillium compact posthole.jpg

Frequency Band120 seconds to 100 Hz 
Sensitivity 754 V/m/s
Size (Diameter x Height)10 x 17 cm
Weight3.1 kg

Trillium Compact Horizon

20250305_100107.jpg

Frequency Band120 seconds to 100 Hz 
Sensitivity754 V/m/s
Size (Diameter x Height)8.6 x 13.8 cm
Weight1.1 kg

Lennartz LE-3D-Lite MkII

LE3Dlite.jpg

Frequency Band1 seconds to 100 Hz 
Sensitivity 400 V/m/s
Size (Diameter x Height)10 x 10 cm
Weight1.9 kg