H5P Content 15063

The images in the slides below are made with the IRIS Earthquake Browser, an imaging tool that compiles data about the location and magnitude of earthquakes, and allows users to view the data in 3D. Earthquakes are shown as bubbles colour-coded for depth, and with size reflecting magnitude. There are three axes to orient users: N-S (north-south), E-W (east-west), and U-D (up-down).

The images show earthquakes from two different plate-tectonic settings: a mid-ocean ridge, and a subduction zone.

Which setting does each slide show?

Slide is the mid-ocean ridge.

Slide is the subduction zone.

Use left and right arrow to change slide in that direction whenever canvas is selected.

Slide 1

Earthquakes are all within the 0 km to 33 km depth range, and fall more or less along the boundary.

Slide 1

Earthquakes fall mostly in the 0 km to 33 km depth range, and cluster along the margin (indicated by the light blue line).

Slide 2

Earthquakes occur at all depth ranges, and become deeper farther from the boundary.

Earthquakes happen over a range of depths, and over a wider geographic area.

Slide 1 shows earthquakes along a mid-ocean ridge, and Slide 2 shows earthquakes in a subduction zone.

The way to tell is that the earthquakes in Slide 1 are shallow, with the majority above 33 km. In contrast, the earthquakes in Slide 2 go to great depth, consistent with a subducting slab of ocean crust. The view from the west (upper right) in Slide 2 even suggests the shape of a slab tilting into the Earth.

Slide 1

Earthquakes fall mostly in the 0 km to 33 km depth range, and cluster along the margin (indicated by the light blue line).

Slide 2

Earthquakes occur at all depth ranges, and become deeper farther from the boundary.

Explanation