Instructions

The interactive dashboard above allows you to explore selected earthquakes that happened within the last year. An up-to-date catalogue of earthquakes is retrieved when the webpage is opened or reloaded from the Incorporated Research Institutions for Seismology (IRIS). The IRIS catalogue is aggregated from data and detections from many organizations around the globe (see earthquake catalogues). We only select earthquakes that are big and/or close enough that the signals are likely to have been recorded on the Ocean Networks Canada instruments.

Map

The map shows the location of all earthquakes available for you to explore as transparent red circles. The size of the circle represents the earthquake magnitude and the colour of the currently selected earthquake is green. Darker red colours indicate regions where several significant earthquakes happened within the last year and circles overlap. Note, the extend of fault lines that rupture during major earthquakes can be hundreds to thousands of kilometres (the 2004 Indian Ocean Tsunami was caused by a magnitude 9.1 earthquake that ruptured a 1,600 km long fault). The locations denoted by the circles only show the location where the rupture started and the uncertainties of that location might be in the order of several tens of kilometers.

Hover your mouse over any circle to get additional information about the event beneath the pointer or click a circle to select the respective earthquake and to update the other dashboard components. The green line that extents from the centre of the selected circle shows the shortest (great circle) distance from the selected earthquake to the Ocean Networks Canada seismometer that is selected (highlighted green) in the data table. Similarly, hovering and selecting works for symbols denoting the locations of seismometer stations.

To explore pan (click and drag) and zoom (click +,-, or use mouse wheel) the map.

Event Table

The event table (right of map) lists all earthquakes that we selected for you to explore. By default the most recent events appear at the top of the table. It is possible to reverse the order of the list or to change the sorting criteria by clicking on the column headers. Click on any event in the list to select it (highlighted green) and to update the other dashboard components. The triangle in the column header indicates the current table order.

Data Table

The data table below the map lists ONC seismometers that should have recorded signals from the earthquake selected in one of the dashboard components above. The first column shows the name (and station code) and also the distance from the earthquake to the instrument. The second column shows the signals recorded by the instruments. Please refer to the seismic instruments and data processing for details about the types of instruments that Ocean Networks Canada has deployed and how the data are processed to suppress noise to highlight the earthquake signals.

Click on any row to select (highlighted green) the corresponding seismometer and to update the map accordingly. Hover over the data traces to learn more about the data.

Background

Instruments

Ocean Networks Canada is using a number of different seismometers to detect earthquakes and other seismic events. The dashboard above currently only shows data from Broadband Seismometers (BBS) except for the Endeavour site located on the Juan de Fuca Ridge and were currently a Short-Period Seismometers (SPS) is installed.

Installation of a short-period seismometer. The titanium pressure case that houses the actual sensors is pushed into a hole that was drilled into a lava pillow at the Endeavour Ridge Segment.