The island of Surtsey Surtsey is the youngest shield volcano of Iceland and originated in a series of eruptions which started with a submarine phase in 1963 and ended by subaerial production of lava and ash in hawaiian style in 1967.

Aside from liquid lava, Iceland’s volcanoes eject gas, ash, cinders, and solid rock (like pumice). Of the roughly 130 volcanoes in Iceland, the most common type is the stratovolcano — the classic cone-shaped peak with explosive eruptions that form a crater in the very top (such as Hekla and Katla, on the South Coast).

The undersea vents that produced Surtsey are part of the Vestmannaeyjar submarine volcanic system, part of the fissure of the sea floor called the Mid-Atlantic Ridge. Vestmannaeyjar also produced the famous eruption of Eldfell on the island of Heimaey in 1973….Surtsey.

Cinder cone, also called ash cone, deposit around a volcanic vent, formed by pyroclastic rock fragments (formed by volcanic or igneous action), or cinders, which accumulate and gradually build a conical hill with a bowl-shaped crater at the top.

Shield volcanoes are almost exclusively basalt, a type of lava that is very fluid when erupted.

There are actually three types of volcanoes namely shield, cinder and composite cones. One example of that is Taal Volcano, a small volcano located in an island at Batangas, Philippines. The composite cone is the famous of all, bearing the shape of a real cone (but not always perfect).

Water accumulated in the vent can cause the eruption from a shield volcano to become explosive. This answer has been confirmed as correct and helpful.

Fluid basalt flows can extend tens of kilometers from an erupting vent. The leading edges of basalt flows can travel as fast as 10 km/h (6 mph) on steep slopes but they typically advance less than 1 km/h (0.27 m/s or about 1 ft/s) on gentle slopes.

To put it simply, a diamond cannot melt in lava, because the melting point of a diamond is around 4500 °C (at a pressure of 100 kilobars) and lava can only be as hot as about 1200 °C.

Then the exposed lava cools and hardens. Despite their ubiquity all over Hawaii’s Big Island, it’s rare for someone to actually fall into a lava tube, experts have said. But it can happen. And on Monday, police said it happened to an elderly man — in his own backyard.

Some will have a touch of sulfur, others will have clay like flavors if weathered. Freshly cooled lava can have smell and taste from roasted trees and other organics that it burned up. Consider that Hawaiian lava cooled in the ocean might taste salty unless the salt was washed away with rain water.