Volcanism Update by Request

I got a question about possible volcanic activity, what implications it can have on the u.s and some analogs to support this.

In response I don't see any major eruptions right now besides a small eruption in guatemala by the name of mount fuego. Heres a quote from the smithsonian weekly report "Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua." I don't think fuego is a threat to the global climate right now because it is only spewing a small amount of ash and its only reaching 1.1km at the most which isn't high enough into the atmosphere to create any disruption to the weather patterns. The ash will eventually get precipitated out within weeks. Besides that all is quite right now. Some other analogs which depict the global cooling effect volcanoes have on the globe include 93-94,94-95,95-6 which followed the mount pinatubo eruptions causing major global cooling as well as a frigid north america.

 There was also the winters of 83-84,84-85 and 85-86 which were frigid across the u.s caused by the major eruption of Mount St Helens. Take note of the +PNA and negative EPO pattern across north america which set up cold winters as well as the high latitude blocking.

Take a look at the global cooling that occurred as a result of so2 that was spewed into the stratosphere  adn converted to volcanic aerosols deflecting incoming solar radiation from the sun. This favours high latitude blocking. This is common in major high latitude volcanoes especially in low solar regimes as we are currently experiencing. Tropical volcanoes do the opposite and cause short term cooling and long term warming because it weakens the easterlies in the pacific and creates an el nino (producing long term global warming). Notice the warming of the last decade caused by little volcanic aerosol's in the stratosphere.

Something very interesting is Katla, a neighbouring volcano to Eyjafjallajökull which some say is overdue for a major eruption. There are signs of higher activity between the much larger and more deadly katla in iceland which may be a sign of an upcoming eruption. Eruption from katla occur on average every 60 years and oddly enough have occurred within months after its neighbouring Eyjafjallajökull erupts. Last July, a flood of water burst from beneath the ice cap on top of Katla, washing away a bridge. This indicates that an extra pulse of heat reached the base of the ice. Since then, there have been erratic movements of the surface of the volcano, measured by precise GPS instruments, and bursts of high earthquake activity beneath Katla’s caldera. These observations imply that magma has risen to shallower depths. Katla’s eruption in 1918 produced five times as much ash as the 2010 Eyjafjallajökull one. A major eruption could result in large parts of Iceland being flooded as snow and ice melted; significant poisoning of Icelandic agriculture; destruction of property; and, of course, the grounding of aircraft across Europe. Also major global cooling will be produced for years to follow if this threat comes to fruition.