Can’t quite make out how close or far they were from Nishinoshima, but it may not be coincidence.
No further activity was reported during 2018. An incandescent lava lake was visible in one of the small craters on both days. Which is a sign that across Vatnajokull and probably Iceland, volcanoes are being recharged with fresh plume magma.Yes and be not supprised If we gets a surtsey – phase in the caldera of Grimsvötn and later a shield – tuya If its a long lived eruption. After spreading by an amount x, the upward force from below is F=(density)*g*x*h , where the density is that of the crust (2 000 kg/m^3), g is the gravitation acceleration, and h is the thickness of the spreading rift. The two decades that followed saw several small sized eruptions of Grimsvotn. Along the NE and SE coasts, yellow-white water was 100-200 m wide and about 1,000 m long.A MODVOLC thermal alert appeared at Nishinoshima on 5 December 2019.
The lava field on the lower side of the NE slope of the cone had thickened, and lava flowed to the N and W. No lava flow was observed reaching the sea, and no significant changes were observed along the coast of the island. This was a large submarine volcano which at some point underwent an explosion. Mostly Caldera man here. It was at that time believed that the volcano would rest for quite some time before erupting again.The volcano proved them wrong as it returned to a state of eruption in April of 2017, an eruption that lasted into August of 2018. So, it’s rather normal to see Grimsvotn doing that, especially as its magma is now very fresh one. Hotspot or the MAR? No thermal anomalies were detected. Explosions are taking place at intervals of several tens of seconds. The Japan Meteorological Agency (JMA) has also provided monthly reports of the eruption.New subaerial activity began on 20 November 2013, almost 40 years after the last recorded island-building event in 1973-74. According to NASA's Earth Observatory, a satellite image of Nishinoshima acquired on 21 June showed a sulfur dioxide-and-steam plume rising from the 2.45-square-kilometer island and drifting NE. A short eruptive event in July 2018 produced a new lava flow and vent on the side of the pyroclastic cone. Between then and November 2015 the island grew from 0.29 to 2.63 kmInformation comes primarily from monthly reports provided by the Japan Meteorological Agency (JMA) and reports and photographs taken by the Japan Coast Guard (JCG), which monitors the volcano due to its remote location in the Pacific Ocean, approximately 940 km S of Tokyo along the Izu-Bonin arc.
A new cone (Crater 3) that emerged in between the first two was first observed on 21 May 2015 with incandescent spatter reaching tens of meters into the air (figure 17).New land area was rapidly forming from lava flows from three active craters and sedimentation of pyroclastic materials around the island in May and June, especially eastward (figure 18).On 13 June 2014 a fourth crater was seen emitting brown ash plumes (figures 19, 20).
Ash plumes rose 500 m and drifted SW. Two vents on the N side of the crater produced lava that flowed to the ocean on the SW coast of the island (figure 54). And at the same time, activity in the West Volcanic Zone (between Langjokull and Reykjanes) comes back to life.But this is a slow process, that takes decades, and too long-term for us humans to pay attention to.I think what we would need would be an estimate of the spreading (in cm) that took place in Reykjanes every century since settlement. Beyond them is where the subduction is taking place and you have a subduction abyss reaching down almost 6000 meters.Ever so slightly north of east of Nishinoshima is where the deepest point is, and the spot where the subducting oceanic crust has the steepest angle.This is a bit of a problem in and of itself as subduction volcanism goes, steep angles of subduction is generally a bad thing for back arc volcanism since the melt would go pretty much straight up, short-pitching for back-arc volcanism to form.In other words, this means that there should really not be a duck around since it would starve to death in a volcanic dessert.Let us instead look at the Graben, those are after all known to on occasion to cause decompression melt as they spread.