What do stratovolcanoes erupt

Agua in Guatemala. Mayon Mt. In detail, however, stratovolcano shapes are more variable than these classic examples, primarily because of wide variations in eruptive style and composition. Some may contain several eruptive centers, a caldera, or perhaps an amphitheater as the result of a lateral blast e. The compositional spectrum of these rock types may vary from basalt to rhyolite in a single volcano; however, the overall average composition of stratovolcanoes is andesitic.

Many oceanic stratovolcanoes tend to be more mafic than their continental counterparts. Characteristics of Composite Volcanoes. What Are the Results of a Volcano Eruption? What Minerals Make Up Pumice? Cinder Cone Lava Flow Effects. Volcano Information for Children. Signs of a Volcano Erupting. This is in contrast to less viscous basic magma that forms shield volcanoes such as Mauna Loa in Hawaii , which have a wide base and more gently sloping profile. Reference Terms. These volcanoes are characterized by a steep profile and periodic, explosive eruptions.

Many stratovolcanoes exceed a height of m. Related Stories. Fuji, Merapi, Galeras, Cotopaxi, and super plenty others. Although they are not as explosive as large silicic caldera complexes, strato volcanoes have caused by far the most casualties of any type of volcano. This is for many reasons. First is that there are so many more strato volcanoes than any of the other types. This means that there will also be lots of people who end up living on the flanks of these volcanoes.

Additionally, strato volcanoes are steep piles of ash, lava, and domes that are often rained heavily on, shaken by earthquakes, or oversteepened by intruding blobs of magma or all of these. This makes the likelihood of landslides, avalanches, and mudflows all very high.

Occasionally as well, entire flanks of strato volcanoes collapse, in a process that has been termed "sector collapse". Of course the most famous example of this is Mt. Helens , the north flank of which failed during the first stages of the big eruption. Helens was certainly not the only volcano to have suffered an eruption such as this, however. Two other recent examples are Bezymianny Kamchatka in , and Unzen Japan in The Unzen sector collapse dumped a flank of the volcano into a shallow inland sea, generating devastating tsunami that killed almost 15, people along the nearby coastlines.

This is a photo of lahar deposits near Santa Maria volcano Guatemala. This used to be a wide, deep river valley, and you can see the far wall of the valley where the trees are growing. The lahar deposits extend from that far wall to behind where this photo was taken. You can see that between lahar events the river cuts into the lahar deposits, but every time there is another event, it fills up again.