earth
Just like water, air and other natural elements, the soil may be considered a resource; it is, however, a non-renewable resource (FAO, 2015; APPA, 2012) – or a potentially renewable one if it is considered from a geological point of…
earth
In order to understand the number of factors that make a water undersaturated or oversaturated, there is an experiment that we can carry out in the kitchen while we wait for the water to boil before cooking pasta. If we…
earth
A hill is a natural rise of the Earth’s surface. Generally, it is less than 600 metres high: it is lower than a mountain and has a less sharp shape. Some hills (so-called building hills) originated from the deposit of…
earth
The longest caves in the world are in Kentucky, the caves of Mammoth, which are 560 metres long. Other long karstic landscapes are in China, on the Shan plateau; in Australia, in the Nullarbar region; in North Africa, on the…
earth
One of the most common beliefs is that in caves the air is often stuffy, unhealthy, low in oxygen content and at times saturated with toxic gases. As a matter of fact, this erroneous belief stems from the confusion between…
earth
In South America plains are different from North to South. Plains in the north are called llanos and they are dry lands in the dry season, while during the rainy periods they are covered by very high vegetation. More in…
earth
Zones that are characterised by a high and anomalous heat flux are those where the release of energy from the ground is greater, however to be able to use this source a fundamental ingredient, together with hot rocks, is water.…
earth
In high mountain or high latitude environments, many caves can contain ice deposits, at times even in great quantities. In winter, the most common cause of ice formation in caves is the freezing of water percolating through fractures and joints…
earth
Rocks embedded a few kilometers below the surface are an ideal habitat too: some microorganisms live in tiny interstitial spaces of rocks which are 3,2 km beneath the subsoil and they are able to tolerate high pressure levels, radiation and…