In parshah Vayeira we read that Hashem destroyed Sodom, which inspired us to learn about natural disasters, starting with volcanoes...
Volcanoes are dramatic evidence of the powerful forces at work inside the Earth. Eruptions of ash, gas and lava destroy entire cities and kill large numbers of people.
Volcanoes also add nutrients to soils, creating perfect conditions for many crops. Some types of volcano make new sections of the tectonic plates that make up the surface of the Earth. Without volcanoes and our planet's plates, the dry land we live on would not be renewed, and weathering and erosion by water, wind and ice would eventually carry it all into the oceans leaving Earth a water world.
There are three common types of volcano: composite volcanoes, often the most deadly; shield volcanoes, which are large but generally less violent; and cinder cones.
Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature; the melted particles then adhere to the turbine blades and alter their shape, disrupting the operation of the turbine. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere (or troposphere); however, they also absorb heat radiated up from the Earth, thereby warming the upper atmosphere (or stratosphere). Historically, so-called volcanic winters have caused catastrophic famines.
Experiment:
This is a model re-enactment of how volcanoes work...
Then, the moment of truth - the pressure becomes too much and at the weakest point, where the sand has bubbles, the hot wax shoots out in a mini volcanic explosion. The entire wax reservoir empties and you get a lovely effect of a flattened top as well, representing how material from the volcanic explosion forms a layer of ash in the atmosphere.
The Ring of Fire is a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur. In a 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements. It has 452 volcanoes (more than 75% of the world's active and dormant volcanoes). The Ring of Fire is sometimes called the circum-Pacific belt.
Tectonic Plates:
The lithosphere, which is the rigid outermost shell of a planet (the crust and upper mantle), is broken up into tectonic plates. The Earth's lithosphere is composed of seven or eight major plates (depending on how they are defined) and many minor plates. Where the plates meet, their relative motion determines the type of boundary: convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The relative movement of the plates typically ranges from zero to 100 mm annually.
Here is a video of a helicopter flight along the rift between two tectonic plates;
This valley is getting 7mm wider every year as the plates are still moving apart.
The rocky valley floor was created by cooled lava.
This valley is surrounded by volcanoes that have formed as the plates move apart.
Copyright © 2016 Educated By Torah