Ist in Lava Wasser?
Lava besteht aus folgenden Stoffen: Silizium, Aluminium, Kalium, Natrium, Magnesium, Kalzium, Eisen, Phosphor, Titan und Wasser. Je nach ihrer chemischen Zusammensetzung fließen Lavaströme auch unterschiedlich. Die Lava kann sehr schnell aus der Förderöffnung oder dem Vulkanschlot fließen.
Wie entsteht Kissenlava?
Kissenlava oder Pillowlava (dieser Begriff wurde 1890 von John Walter Gregory geprägt) ist unter Wasser erstarrte Lava von kissenartiger Form und gilt daher als sicheres Indiz für subaquatischen Vulkanismus. Fließt weitere Lava nach, reißt die Hülle an einer Stelle auf und weitere Kissen entstehen.
How are AA and pahoehoe lavas different?
There is no systematic chemical difference between aa and pahoehoe lava. Lavas with the identical compositions can form both aa and pahoehoe. Lavas that have slight chemical differences tend to have different temperatures and viscosity’s but the critical factor influencing the transition from pahoehoe to aa is the viscosity of the lava.
What are the different types of basaltic lava flows?
There are three types of basalt lava flows: pillow, pahoehoe, and a’a. Pillow lavas are volumetrically the most abundant type because they are erupted at mid-ocean ridges and because they make up the submarine portion of seamounts and large intraplate volcanoes, like the Hawaii-Emperor seamount chain.
What causes the conversion of pahoehoe to A’a?
The pahoehoe-to-a’a conversion can be caused by either an increase in flow viscosity, or an increase in the rate of shear. Cooling, gas loss, and crystallization of the lava will cause it to become increasingly more polymerized and viscous as it advances farther downslope.
What kind of lava forms smooth ropy lava?
Image Credit: R. W. Decker/USGS July 02, 1983. If lava cools slowly and does not move too fast it forms smooth ropy lava called pahoehoe. However, if it cools quickly and moves fast it can tear into clinkery pieces called a’a. Temperature and gases certainly influence whether the lava becomes aa or pahoehoe.