# Volcanoes and Eathquakes **URL:** \ **Category:** Factual Questions\ **Created:** [March 11, 2015, 6:28pm UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770 "2015-03-11T18:28:07Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [March 11, 2015, 6:28pm UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770/1 "2015-03-11T18:28:07Z")
I read somewhere that it’s not unusual to have increased earthquake activity associated with volcanic eruptions. Does that mean there is a relationship between volcanoes and earthquakes, or could it be just a coincidence? One can imagine that volcanoes might release pressure that might otherwise increase earthquake activity, but that could just be nonsense. Does volcanic activity increase, decrease or have little effect on the number of earthquakes in a specific area? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [March 11, 2015, 6:34pm UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770/2 "2015-03-11T18:34:10Z")
Volcanoes and earthquakes certainly do have an association, but not all earthquakes are caused by volcanoes. If the sub-ground is moving with magma flowing, you can betcher ass there will be earthquakes nearby. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 11, 2015, 9:28pm UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770/3 "2015-03-11T21:28:23Z")
> [@dolphinboy](#): > > Does volcanic activity increase, decrease or have little effect on the number of earthquakes in a specific area? It’s more that _some_ volcanic activity (e.g. US West Coast, Japan) and major earthquake zones are caused by [the same thing](http://en.wikipedia.org/wiki/Convergent_boundary) But not all volcanoes are strongly associated with quakes. So-called [“hot spot”](http://en.wikipedia.org/wiki/Hotspot_%28geology%29) volcanoes (Hawaii, for instance) are different and aren’t _necessarily_ as associated with quakes… ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [March 11, 2015, 9:40pm UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770/4 "2015-03-11T21:40:25Z")
You sometimes hear about “earthquake swarms” that are attributed to magma moving around underground and which can _sometimes_ be a predecessor to a volcanic eruption. For example Yellowstone has them fairly regularly. However, most of the earthquakes associated with these swarms are fairly deep and fairly low magnitude so they’re usually not even noticeable without instruments let alone damaging. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [March 12, 2015, 1:19am UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770/5 "2015-03-12T01:19:33Z")
There was a very active volcano in Iceland from August 2014 through a couple weeks ago. [Bárðarbunga - Wikipedia](http://en.wikipedia.org/wiki/B%C3%A1r%C3%B0arbunga) Here’s the Icelandic government’s English-language webpage giving the day-by-day behavior of the volcano in March. [Bárðarbunga and Holuhraun - overview | Articles | Icelandic Meteorological office](http://en.vedur.is/earthquakes-and-volcanism/articles/nr/2947) The first couple paragraphs include links to the earlier month’s day-by-day pages. If you read the volcano’s history starting in August you’ll see it announced itself with massive earthquake swarms, then ground swelling and eventually lava on the surface. It was pretty exciting to follow day to day when nobody knew what was going to happen but they were concerned it could get really, really big. A huge amount of lava migrated from under the volcano to another area about 20 miles away. A lot of rock got stretched and moved in the process, with a lot of earthquake action. The wiki article about the eruption at [2014–2015 eruption of Bárðarbunga - Wikipedia](http://en.wikipedia.org/wiki/2014%E2%80%9315_eruption_of_B%C3%A1r%C3%B0arbunga) is also pretty good. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [March 12, 2015, 2:58am UTC](https://boards.straightdope.com/t/volcanoes-and-eathquakes/714770/6 "2015-03-12T02:58:15Z")
> [@MrDibble](#): > > It’s more that _some_ volcanic activity (e.g. US West Coast, Japan) and major earthquake zones are caused by [the same thing](http://en.wikipedia.org/wiki/Convergent_boundary) > > But not all volcanoes are strongly associated with quakes. So-called [“hot spot”](http://en.wikipedia.org/wiki/Hotspot_%28geology%29) volcanoes (Hawaii, for instance) are different and aren’t _necessarily_ as associated with quakes… These volcanoes behave very differently too. The “Ring of Fire” volcanoes on the US West Coast and Japan tend to be very explosive. They sit dormant for long periods of time, but when they decide to go **kablooie** , they go **K A B L O O I E ! ! ! ! !** and blow up all at once with a mighty explosion. The Hawaiian-style volcanoes, however, just sit there and chronically burble and fume and splatter and drool magma, like putting candles into a straw-wrapped wine bottle and letting the wax dribble down the sides. They don’t do the big sudden explosions like the others do.