{"id":2030,"date":"2026-06-26T19:56:05","date_gmt":"2026-06-26T19:56:05","guid":{"rendered":"https:\/\/cnnglobalnews.com\/2026\/06\/26\/from-seismic-doublets-to-earthquake-swarms-what-do-we-know-about-this-weeks-global-tremors\/"},"modified":"2026-06-26T19:56:05","modified_gmt":"2026-06-26T19:56:05","slug":"from-seismic-doublets-to-earthquake-swarms-what-do-we-know-about-this-weeks-global-tremors","status":"publish","type":"post","link":"https:\/\/www.cnnglobalnews.com\/?p=2030","title":{"rendered":"From \u2018seismic doublets\u2019 to \u2018earthquake swarms\u2019 \u2013 what do we know about this week\u2019s global tremors?"},"content":{"rendered":"

The chain of earthquakes that shook the planet this week was violent and tragic, but can be explained<\/strong><\/p>\n<\/p>\n

A string of powerful earthquakes struck different parts of the world on Wednesday, prompting speculation over whether the events could be connected. While seismologists say they were not, the unusual cluster has raised questions about how earthquakes are linked, why some occur in pairs, and what terms such as \u201cseismic doublet\u201d<\/em> and \u201cearthquake swarm\u201d<\/em> actually mean. <\/p>\n

What happened?<\/h2>\n

The week\u2019s most devastating seismic event struck Venezuela, where two powerful earthquakes measuring magnitude 7.2 and 7.5 hit just 39 seconds apart near the country\u2019s northern coast, killing hundreds of people and causing widespread destruction. <\/p>\n

Hours later, a magnitude 6.9 earthquake struck off northern Japan, followed by a magnitude 5.6 tremor in northern California. Several smaller earthquakes were also recorded near the Philippines and Papua New Guinea.<\/p>\n

\n
\n An infographic titled ‘Major earthquakes along the Pacific Ring of Fire over the last 24 hours’ created on June 25, 2026.<\/p>\n


\n \u00a9\u00a0Getty Images \/ Yasin Demirci\/Anadolu <\/span>
\n <\/figcaption><\/figure>\n

Most of the earthquakes shown on the map occurred along the Pacific Ring of Fire, a horseshoe-shaped belt around the Pacific Ocean that accounts for about 90% of the world\u2019s earthquakes. Venezuela, however, lies outside the Ring of Fire, with its earthquakes occurring on the boundary between the Caribbean and South American tectonic plates.<\/p>\n

The language of earthquakes<\/h2>\n

The rare back-to-back shocks that hit Venezuela are considered a \u201cseismic doublet,\u201d<\/em> one of the terms seismologists use to describe how earthquakes occur and how they may relate to one another.<\/p>\n

A seismic doublet refers to two earthquakes of similar strength occurring close together in time and location.<\/p>\n

An aftershock is a smaller quake that follows a larger one as the crust adjusts after the initial rupture. Aftershocks can continue for days, weeks or even longer.<\/p>\n

An earthquake swarm is a series of quakes in one area without one clearly dominant mainshock. Swarms are different from a mainshock-aftershock sequence because there may be no single obvious \u201cmain\u201d<\/em> event.<\/p>\n

\n
\n A view of a collapsed building in a Caracas neighborhood on June 25, 2026 in Caracas, Venezuela.<\/p>\n


\n \u00a9\u00a0Getty Images \/ Edilzon Gamez <\/span>
\n <\/figcaption><\/figure>\n

Another important concept is stress transfer. The term refers to changes in stress caused by one earthquake that can increase the likelihood of another occurring on a nearby fault. But this phenomenon usually applies over much shorter distances, not across continents or oceans.<\/p>\n

Were Wednesday\u2019s tremors linked?<\/h2>\n

The timing prompted speculation on social media that the earthquakes on different sides of the world could be related. However, experts say there is no evidence of a global seismic chain reaction.<\/p>\n

Russian geophysicist Pyotr Shebalin, director of the Institute of Earthquake Prediction Theory and Mathematical Geophysics at the Russian Academy of Sciences, told Ren TV that the Venezuelan and Japanese earthquakes were \u201cpure coincidence\u201d<\/em> and that there was \u201cno pattern\u201d<\/em> connecting the two events.<\/p>\n

According to Shebalin, the Venezuela earthquake was not unexpected because the country lies on the boundary between the Caribbean and South American tectonic plates, a well-known seismic zone. Japan is also located on active plate boundaries, but the two countries belong to different tectonic systems and involve different fault mechanisms, making a direct connection between the earthquakes unlikely.<\/p>\n

\n Read more<\/strong><\/span><\/p>\n

\n \"RT\"
Venezuela earthquakes: Over 50,000 reported missing as international relief efforts ramped up (PHOTOS, VIDEOS)<\/a><\/figcaption><\/figure>\n<\/blockquote>\n

US experts have reached the same conclusion. Martin Hudson, an adjunct professor of civil and environmental engineering at the University of California, Los Angeles (UCLA), told The Guardian that \u201cif you look at the last 100 years of earthquakes, we\u2019ve never seen earthquakes this far apart be related.\u201d<\/em><\/p>\n

<\/em><\/p>\n

Why did they happen on the same day?<\/h2>\n


<\/em>The United States Geological Survey (USGS) estimates that several million earthquakes occur worldwide each year, although the vast majority are too small to be felt. On average, about 15 reach magnitude 7.0-7.9 \u2013 classified as major earthquakes \u2013 while roughly one exceeds magnitude 8.0, a category known as a great earthquake. Such figures illustrate why clusters of powerful earthquakes can occasionally occur by chance, even if they are not physically related.\u00a0<\/em>
<\/em>
\u201cEarthquakes happen every day all over the world. Most of them happen far from people,\u201d William Barnhart, assistant coordinator for the USGS Earthquake Hazards Program, <\/em>told The Guardian. He described this week\u2019s sequence as \u201ca very peculiar day,\u201d <\/em>rather than evidence of a global seismic chain reaction.<\/p>\n

\n Read more<\/strong><\/span><\/p>\n

\n \"RT
RT staff caught in deadly Caracas earthquake<\/a><\/figcaption><\/figure>\n<\/blockquote>\n

Can scientists predict the next major earthquake? <\/p>\n<\/h2>\n

No. Scientists can identify high-risk zones, monitor fault lines, estimate long-term probabilities, and track aftershocks after a major event. But they cannot predict the exact time, place, and magnitude of the next major earthquake. <\/p>\n

The best they can do is assess risk and issue warnings after a quake has already happened, such as tsunami alerts or aftershock forecasts. <\/p>\n

The inability to predict earthquakes has real-world consequences. The twin earthquakes in Venezuela struck on Battle of Carabobo Day, one of the country\u2019s most important national holidays, when official ceremonies, parades, and commemorative events were taking place across the country. Had scientists been able to forecast the exact time and location of the quakes, many of those gatherings could have been postponed or people evacuated.<\/p>\n","protected":false},"excerpt":{"rendered":"

The chain of earthquakes that shook the planet this week was violent and tragic, but can be explained A string of powerful earthquakes struck different parts of the world on … Read More<\/a><\/p>\n","protected":false},"author":0,"featured_media":2031,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-2030","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-world-news","entry"],"_links":{"self":[{"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=\/wp\/v2\/posts\/2030","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2030"}],"version-history":[{"count":0,"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=\/wp\/v2\/posts\/2030\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2030"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2030"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cnnglobalnews.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2030"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}