Well, Kilauea volcano is erupting once again, after taking a two-year break. Kilauea volcano is located on the southeastern side of the big island of Hawaii, and before this recent break, was in a nearly constant state of eruption over the previous 25 years. This map shows the location of the summits of the main volcanoes on the big island, and the current eruption is located in the summit caldera of Kilauea.
Prior to the big eruption down on the northeast rift zone of Kilauea south of Hilo, there had been a lava lake in the summit caldera that was fed by the magma chamber under the caldera floor. That magma drained northeastward and fed the 2018 eruption on the northeast rift zone, leaving a void under the caldera floor. That, in turn, led to the collapse of the caldera floor by over a hundred meters across a large area, and several hundred meters at the deepest point.
This overview flight shows the extent of the collapse that occurred in 2018. The deep pit is presumably centered over the location of where the magma chamber was and as the drone pans around here you can see the level of the original caldera floor on the left along with the main caldera wall.
The deep crater that developed in the collapse zone eventually started filling with water since it was lower than the water table. A very hot and slowly growing lake of acidic water has been present the last couple of years, but that ended a few days ago when lava started pouring out of three locations on the crater wall. So, this obviously is a clear indication that magma has returned to the summit of Kilauea.
This image here shows the lake of hot water on the left from December 20th before the eruption started and then two days later when lava was pouring into the crater. The lava lake is now already much deeper than the water lake was and is steadily growing.
A spectacular video from the night of the 20th shows the lava flowing into the crater which can be seen in the video at the bottom of this post. The lava of course boiled off the water that was in the crater and this initially created some very large steam explosions. The clip below shows the huge clouds of steam and ash pouring out of the crater.
Note that once the water boiled off, the steam explosive interaction between the lava and the water ended, and so the amount of steam and ash coming out of the crater is now far less. Here is a still image showing that the steam and ash cloud was pretty tall and it did deposit a layer of ash downwind of the crater as you can see below.
It is unknown how long this current eruption will last, but eventually, lava will fill in the crater that formed during the partial collapse of the caldera floor. In just a couple of days, the level of the lava lake has risen by 515 feet or over 150 meters, and the level of the lava lake will likely continue to rise in the coming days.
This type of activity happens over and over again at Kilauea based on what is known of the geology there. Eventually, the expanding lava lake may even fill in the portions of the caldera floor that subsided in 2018 as well, returning the caldera back to a state that is closer to what was previously seen. Anyway, this will be interesting to watch in the coming days and weeks.