BGS LEGO seismometer

Build a BGS LEGO seismometer

Seismometers have been around for nearly 200 years. Some historical instruments show that designs can be very simple. The earliest seismic sensors were just simple pendulums that swung when a nearby earthquake occurred.

You can make your own simple seismometer from Lego and a metal spring. The mass on the sensor will stay still (due to its inertia) when the ground moves, this relative motion can then be converted to a voltage with a coil and a magnet.

Users in education can make their own version of the BGS Lego seismometer under a Creative Commons licence. See Terms and conditions below for further details.

1) Start with the hinge

Building the hinge part 1
Building the hinge part 2
Building the hinge part 3
Building the hinge part 4
Building the hinge part 5

Using a piece of 500 micron card or plastic as a spacer, the hinge is made from double thickness of tape.

Building the hinge unit part 1
Building the hinge unit part 2

2) Make the armature

Building the armature part 1
Building the armature part 2
Building the armature part 3
Building the armature part 4
Building the armature part 5

The spring is held tight between two 2x4 LEGO bricks.

Securing the spring part 1
Securing the spring part 2

The hinge unit is added at this stage.

Adding the hinge unit part 1
Adding the hinge unit part 2

3) The base and completed assembly

Building the base part 1
Building the base part 2
Building the base part 3
Building the base part 4
Building the base part 5
Building the base part 6
Building the base part 7
Building the base part 8
Building the base part 9

The hinged armature is added to the base.

Adding the armature to the base.

The other end of the spring is bent over and clamped between two 1x8 LEGO bricks.

Bending and clamping the spring.

Finally, a weight is added so that the sensor is balanced and free to move.

Adding a weight to balance the sensor.

What additional equipment do I need to start detecting earthquakes?

You'll need a few more bits of kit before you can start detecting earthquakes with your Lego seismometer:
  • coil
  • magnet
  • mass
  • USB digitiser/seismometer interface
  • PC, Mac or RaspberryPi computer
  • jAmaSeis software

For further details go to seismometers, software & datalogging.

Terms and conditions

Non-commercial users can make their own version of the BGS Lego seismometer under a Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0).

This licence means that non-commercial users are free to:

  • Share — copy and redistribute the material in any medium or format
  • Adapt —remix, transform, and build upon the material

But, if you publish a copy, you must adhere to the following terms

Creative Commons License

LEGO seismometer data from a UK school

The LEGO sensor at Hazel Community Primary School, Leicester, has also been busy recording signals from distant earthquakes .

For comparison, images are shown alongside data from the BGS professional seismometer CWF located in a quiet vault in Charnwood Forest near Loughborough.

Date Location Magnitude Image Data file
21/11/2016 Japan 6.9 Seismograph of earthquake on 21/11/2016 in Japan, magnitude 6.9 NA
03/12/2016 Alaska 5.9 Seismograph of earthquake on 03/12/2016 in Alaska, magnitude 5.9 .sac
06/12/2016 Trinidad 6.0 Seismograph of earthquake on 06/12/2016 in Trinidad, magnitude 6.0 .sac
06/12/2016 Sumatra 6.5 Seismograph of earthquake on 06/12/2016 in Sumatra, magnitude 6.5 .sac
08/12/2016 China 6.0 Seismograph of earthquake on 08/12/2016 in China, magnitude 6.0 .sac
08/12/2016 Solomon Islands 7.8 Seismograph of earthquake on  08/12/2016 in Solomon Islands, magnitude 7.8 .sac

The data files recorded during the matches can be downloaded in .sac data format. Free software for reading and analysing this data is available (Seisgram2k or Winquake).


Contact Paul Denton, UK School Seismology project leader, for further information.