Setup of a Monitoring Station

From a practical, logistical point of view one distinguishes between two types of seismological observation stations: permanent (or long-term) installations and temporary (short or medium-term campaign) measurements. The ways and reasons for installing one or the other type of station vary between these two categories.

Station SBUB

Station SBUB

The primary goal of permanent stations is to monitor seismicity, the activity of earthquakes with time. Therefore the longer we measure, the more we know about the behaviour of the underground.

Two kinds of sensors are used at seismic stations:

  • Broadband sensors that are designed to detect even the smallest ground vibrations from very small nearby earthquakes (magnitude M<1) as well as regional and teleseismic (distant) events. Earthquakes of Magnitude 5 and more can even be recorded from the other side of the globe.
  • Strong motion sensors (“accelerometers”) record strong ground motion from nearby large earthquakes.

In Switzerland, the SED operates about 45 broadband stations located at remote and quiet sites with little background noise. The approximately 60 strong motion stations are mostly placed within cities in order to characterise the motions in the areas of high risk from rare large earthquakes. More on this as well as on the SED’s permanent networks can be read here.

The locations of the permanent stations are chosen from a scientific point of view. It is not only important to place a station close to the expected region of seismicity; it is at least as important to construct a network of stations that covers well the sources of seismicity, from all directions. Earthquakes can only be accurately located if they are recorded by many stations, some close to the epicentre, with good distribution in all directions.

Watch a short film showing the installation of a seismic station at the Mont Terri Rock Laboratory by the Swiss Seismological Service in early 2014:

Follow the construction of a permanent seismic station on the Lauchernalp (Lötschental) in the picture gallery:

Temporary stations are usually installed with a goal to be reached within a given time frame. This can vary on a wide range but is usually between a few hours and a few years. Typical scientific targets for temporary stations are the investigation of specific structures in the Earth, a particular earthquake sequence or other seismically detectable events (natural or man-made).

Follow the construction of a temporary seismic station in Bhutan in the picture gallery:

This time-lapse video shows how a cement platform is prepared in the basement of a house:

This time-lapse movie illustrates the installation of two solar panels and their connection to the instruments located inside the building: