Earthquakes cannot affect climate

A podcast with more than 800 plays on iVoox that is also available on other platforms like Castbox and Spotify claims that earthquakes can “affect climate” because they “influence ocean currents”, which are elements that regulate the climate.

This claim is MISLEADING. The oceans are climate regulators and ocean currents serve as vehicles that redistribute energy, which can influence climate insofar as it moves heat and moisture from the equator to the poles and vice versa. However, and according to the experts Verificat consulted, there is no evidence that earthquakes have any influence on ocean currents. There are also no signs that they influence climate.

Ocean currents [influence the climate] because they send large quantities of cold or warm water to different places […] And everything that influences ocean currents influences the climate, including earthquakes. As a result, an earthquake can affect climate.

Ocean currents help regulate the climate, according to the National Oceanic and Atmospheric Association (NOAA), in that they allow warm waters to reach the poles and for cold waters to return to the tropics. Earthquakes, however, do not affect these “conveyor belts”, which are influenced by surface winds, temperature and salinity gradients, the rotation of the Earth and tides.

The influence of earthquakes on climate and climate on earthquakes is a subject of constant study. At this point, speculations have only been made about a relationship in certain climates with microseismicity, or “tiny earthquakes with magnitudes less than zero”. Specifically, scientists think there could be a correlation between atmospheric pressure changes caused by large storms, such as hurricanes, which can occasionally trigger “slow earthquakes”, which release energy over relatively long periods of time, without making the ground shake in the way typical earthquakes do.

Currents do not depend on earthquakes

The presence or alteration of ocean currents is not determined by the onset of earthquakes, as the podcast argues. “Earthquakes have an impact on solid earth and can be caused by many things: from plate tectonics and different types of fault activity to volcanic activity”, explains Francisco J. Doblas-Reyes, director of the Earth Science department at the National Barcelona Supercomputing Center (BSC-CNS), and one of the authors of the latest reports by the IPCC, the leading scientific body in the assessment of climate change, explains to Verificat.

When they occur underwater, earthquakes are called seaquakes, but they never “affect ocean currents”, the expert specifies, because the currents “have spatial scales ranging from thousands of kilometres to hundreds of metres, caused by the wind and variations in sea density (which are produced by the addition of fresh water or evaporation)”, and not by earthquakes, he insists.

It is true that there is an area of research that observes how “occasional events such as huge storms and underwater earthquakes can also trigger deep ocean currents, moving masses of water inland when they reach shallow waters and coastlines”, as NOAA explains in this article.

In any case, there is no evidence that such events have an impact that lasts long enough to change the climate of a particular region today, although scientists have hypothesised it occurring in the past: “Since its formation, the Earth underwent many climatic changes that were clearly influenced by the ocean currents produced by the drift of continents”, Sara Figueres, head of the Geophysics and Seismology department of the Cartographic and Geological Institute of Catalonia (ISCG), explains to Verificat. “These processes are very slow – we are talking about hundreds of millions of years”, she continues.

On a local or human scale, adds the expert, “or as far back as generations and generations of memory can stretch, the effect of an earthquake on ocean currents is negligible. Even if an earthquake produced a tsunami, it would have no effect on ocean currents”, she concludes.