Groundbreaking earthquake discovery: Risk models overlook an important element

According to new research from the University of Copenhagen, earthquakes affect the movement of Earth's tectonic plates, which in turn could impact on future earthquakes. The new knowledge should be incorporated into the computer models used to gauge earthquake risk, according to the researchers behind the study.

The surface of our planet is divided into larger and smaller pieces by the plates on our planet. The pieces are in motion because of the fluid-like part of Earth's mantle. These movements can cause earthquakes, which can ruin cities and kill thousands of people. In 1999, the strongest European earthquake in recent years, the town ofzmit, Turkey, took the lives of 17,000 of its residents.

As plates move against one another, energy is slowly accrued along plate margins, and then suddenly released via earthquakes, which is accepted by researchers and earthquake experts. This happens over decades or century-long intervals in a constant stick-slip motion.

The behavior of the plates can change following an earthquake according to a new study.

The researchers have been able to conclude that the Anatolian continental plate has changed direction since the 1999 earthquake. The data shows that the earthquakes around Turkey were influenced by this.

It appears that the link between plate motion and earthquakes is not a one-way street. The study's lead author, Juan Martin De Blas, explains that earthquakes feed back, as they can cause plates to move differently afterwards.

The pattern of the later earthquakes is affected by the plate movements. If a plate shifts direction or moves at a different rate than before, this could have an impact on the seismicity of its margins with neighboring plates.

The models of quae can be improved.

According to the researchers, the new findings provide a clear basis for reexamining the risk models that interpret the data gathered from the monitoring of plate movements. The data is used to assess the risk of future earthquakes in terms of probability.

The assumption that plate movements remain constant is an important aspect of these models. This is not the case with this study. The models can now be further evolved so they take into account the feedback mechanism that occurs after an earthquake, says Associate Professor Giampiero Iaffaldano.

According to the researchers, the assumption that plate movements are constant has largely been a necessary one, because monitoring plate motions over a few years was no longer possible. We can track plate motion changes over a long period of time thanks to the advent of geodesy and the use of gps devices.

It could make us better at assessing risk.

From place to place, how tectonic plates are monitored varies. Near the edges of a plate, gps transmitters are positioned preferentially. The movement of plate boundaries can be tracked by public agencies and researchers. According to the researchers, we can benefit from even more gps devices continuously monitoring plate interiors away from their margins.

Plates as a whole are poorly represented by the plate boundaries. The data from the monitors positioned farther away from the plate boundaries should be used more. Giampiero Iaffaldano says that this can inform us about weather plates changing motion and how, and provide information useful for assessing the risk of future events somewhere other than the known hot-spots.

The study is limited to the Anatolian continental plate, as thezmit earthquake is one of the few events in which a combination of sufficient seismic andGPS data is available. They think the picture is the same for other plates.

More information: J Martin de Blas et al, Have the 1999 Izmit–Düzce earthquakes influenced the motion and seismicity of the Anatolian microplate?, Geophysical Journal International (2022). DOI: 10.1093/gji/ggac020 Journal information: Geophysical Journal International Citation: Groundbreaking earthquake discovery: Risk models overlook an important element (2022, March 15) retrieved 17 March 2022 from https://phys.org/news/2022-03-groundbreaking-earthquake-discovery-overlook-important.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.