For Those Below Trivia Quiz

Answer: Solutional cave

Solutional caves are the most common type; they are formed when a solution of acid in groundwater seeps through faults and crevices in rock to create cracks and fissures which expand over time. The most common soluble rock in which caves are formed is limestone which dissolves through the action of carbonic and other acids - this process is known as carbonation, hence Flopsy's flash of inspiration. Carbonation of limestone (and other rock such as gypsum and dolomite) produces a landform known as 'karst', which is characterised by underground drainage systems, aquifiers... and caves.

Answer: Lava tubes

Sometimes a cave is formed when the rock is still molten, or liquid, as part of a volcanic process. A solid crust is formed on the surface where the air is cool but the lava goes on flowing underneath the crust until the volcano stops erupting. The flowing lava creates channels; the centre of the channels stays hot as the outside cools, forming walls around the inner core. The lava continues to flow until its source is blocked by cooled rock and no new sources are created; furthermore, because the cooled external surface insulates the lava, it remains molten and continues to flow downhill until, put simply, it runs out - draining the channels, or tubes, behind it. By the time it stops flowing, the lava may have covered a considerable distance - some lava tubes extend more than forty miles from their source.

The longest and most extensive lava tubes are on the Big Island of Hawaii but others are found in Portugal, Spain, Iceland, and the western USA as well as other volcanic regions. In addition, there are known to be lava tubes on Mars where the sides of Olympus Mons are covered in lava channels.

Ralph is claiming copyright on the other sorts of caves; he made those up and thinks that llama caves have a nice ring to them. Flopsy thinks he has bells on the brain and bats in the belfry.

Answer: Sea cave

Sea caves can be caused by water eroding the land that forms the edge of the coastline or by an existing cave being flooded by seawater that continues the process of erosion. Sea caves sometimes become penetrable above the sea line when earth movements push the land upwards. Most sea caves are fairly short in length, approximately 20 metres (60 feet) on average, but Fingal's Cave (on the Scottish island of Staffa) is approx. 70 metres (230 feet) long. It is made of hexagonal columns of basalt, similar in structure to the Giant's Causeway which is across the sea in Northern Ireland - both were formed by the same lava flow about 50-60 million years ago.

Ralph invented the other sorts of cave, he's waiting for a composer to immortalise his thoughts so that he can get royalties; Flopsy hopes that he doesn't expect to spend them anytime soon.

Answer: Austria

Ice caves are not actually made of ice, they are caves that contain ice formed from water flowing into the cave, even if the flow is more like a drip. Ice caves usually have a high entrance which allows cold air to flow in but these caves are also usually closed off at the bottom; as cold air is heavier than warm air, it flows into the cave and is trapped - and of course, to form ice, the temperature must be at or below freezing.

The Eisriesenwelt is the largest ice cave in the world; a natural limestone cave, it is situated inside the Hochkogel mountain about forty km from Salzburg. There are several entrances to the Eisriesenwelt which allow air in. The temperature of the air intake varies according to the temperature outside the mountain - warmer air flowing in during the summer circulates upwards, colder winter air travels downwards and reduces the temperature inside the lower areas. In spring, when snow melts on the mountain, water seeps through the rock and when it reaches the lower, colder parts of the caves, it freezes to make ice in spectacular formations. The halls of the Eisriesenwelt contain huge towers of ice, frozen waterfalls, columns, and other sorts of ice formations made possible by the complex pattern of airflow into and through the caves.

'It looks beautiful but it's freezing my, er, tail off, let's go somewhere to warm up!' said Ralph.

Answer: Up to 58 degrees C (136F) with 90-99% humidity

The Cave of the Crystals was discovered in 2000 as part of new diggings for the Naica mining complex in Mexico. Caves had been discovered there before but this one is noteworthy because of the sheer scale of the crystals of selenite (a form of gypsum) found within it. Crystals found in the cave, about 300 metres (980 ft) below the surface, are some of the largest ever found on Earth, growing up to 12 metres (39 ft) long and 4 metres (13 ft) across.

As we descend in the Earth's crust, the temperature rises about three degrees centigrade per 100 metres. In mines, this entails the construction of ventilation systems or miners would soon overheat, risking death. However, caves are often complex systems with good air circulation, and the temperature, once past the entrance, is usually fairly constant irrespective of the season or temperatures above ground.

While the temperature of the Cave of the Crystals is constant, it is remarkable for its heat with temperatures up to 58C and 90-99% humidity. No human can withstand those temperatures for more than ten minutes and even with specially-designed refrigerated suits, the longest period that can be survived in the cave is about 30 minutes. Even rabbits and llamas can't stand those temperatures so Flopsy and Ralph beat a hasty retreat.

Answer: A dog's cave

Strictly speaking, a dog's cave isn't a type of cave in its own right; it's likely to be a lava tube or even a mineshaft or quarry, but the shape of the cave and the way the ground slopes mean that volcanic vapours (particularly carbon dioxide) collect at the bottom of the atmosphere in the cave. The gases are produced via a volcanic feature called a 'fumarole'. Many fumaroles discharge their carbon dioxide into groundwater and the resulting mineral water is often used for therapeutic purposes. As carbon dioxide is heavier than oxygen, if it is discharged as a gas it sits just above floor level. Humans, and llamas, rarely notice this as they are tall enough to breathe in oxygen but smaller animals, like rabbits and dogs, breathe in a high concentration of carbon dioxide and the absence of oxygen in their lungs makes them pass out.

There are many stories about dogs being taken into caves and then falling unconscious for no apparent reason. If their owners take them out of the cave quickly enough, the dogs recover as carbon dioxide is not poisonous, it is only the lack of oxygen that produces the ill effect. The most famous dog's cave is in Italy; the Grotto del Cane near Naples was described by various authors including Pliny the Elder in Roman times, and Mark Twain in the nineteenth century when the cave was a major tourist attraction. If you should ever enter a dog's cave, take a tip from Ralph and don't lie down to take a nap - you're only taller than a dog, or rabbit, when you're standing up.

Answer: 400 miles (643 km)

Mammoth Cave is the longest cave system known in the world. The caves are within a US National Park in Kentucky which was made a World Heritage Site in 1981. The Park centres round the Green River, into which the waters flowing through the cave drain. The geology of Mammoth Cave is primarily limestone capped with a sandstone layer known as the Big Clifty. This type of sandstone dates from the Pennsylvanian subperiod, part of the Carboniferous period. This means that Big Clifty is approximately 300 million years old and was formed around the same time as the coalfields in Pennsylvania, from which the subperiod takes its name.

Human beings first used the caves about 6,000 years ago and several sets of Native American remains have been discovered there; most of them were the result of funerals that took place long before the arrival of Columbus in the New World. The caves are also home to more than 130 species of fauna, many of which are endangered - including the albino and blind Kentucky cave shrimp.

Flopsy decided that she wasn't interested in shrimp she couldn't eat and started to read her tourist guide to big holes in the ground. Suddenly she yelled at Ralph. 'The world's second largest cave system is in Mexico,' she said, 'at Sistema Sac Actun and not only is the weather nicer there, guess what they've found?' Ralph looked bored but asked what it was. 'A mastodon!' Flopsy cried, 'Let's go!'

Answer: Shawls

In caves formed by a solution of water and carbon dioxide, the water continues to flow after the cave has been created, sometimes changing the shape of the cave or creating new caves, and sometimes forming underground streams or rivers. Most water entering the cave will be via a process of seepage, single drips of water may combine with other drips to form a flow or they may simply drip from ceiling to floor. The water deposits some dissolved calcium carbonate wherever it touches a surface, occasionally leaving traces of other minerals carried from the soil and rocks above. This process is what produces cave formations or speleotherms to give them a more accurate name.

There are several types of speleotherms of which dripstone and flowstone form the largest formations. Dripstone is formed when water drips slowly from the roof of a cave, initially forming thin straws of calcite which later thicken to become stalagmites and stalactites - and they in turn will become columns and pillars.

Flowstone occurs where a film of water leaves a layer of calcite behind. The calcite can develop folds and sometimes the lower part of the formation hangs free from the rock, thus creating the appearance of a shawl. The caves at Yarrangobilly in Australia's Snowy Mountains contain many spectacular examples of shawls, many coloured pink and orange by iron oxides. The caves also have other flowstone formations, some coloured black and grey as a result of bushfires overhead many centuries ago.

'I can't wear one of those shawls,' Ralph grumbled, 'they're much too hard for me; I'd rather go for a walk on that mountain,' and with that, Ralph climbed into a passing chairlift and went up Mount Kosciuszko.

Answer: They breathed out carbon dioxide

One aspect common to deep caves like Altamira is that most conditions remain fairly constant over long periods of time - temperature, humidity, and other atmospheric factors change very little and very gradually, insulated as they are from external climatic fluctuations. Unfortunately this natural balance can be disturbed once caves are re-discovered by humans after centuries of isolation. People like to visit sites like Altamira to view prehistoric art that has survived for millennia and thus they become centres for tourism. But the introduction of large numbers of people poses problems of several kinds - keeping them safe and away from the paintings (or rock formations, rivers, and hazards) may entail the construction of things like walkways, stairs, and bridges thus disturbing the cave soil and causing other ecological disruption.

Humans also bring atmospheric disturbance with them - they breathe in the dry air and breathe out moist carbon dioxide. While a solution of carbon dioxide is essential to the formation of most caves, it is also detrimental to the ancient paints and charcoals used in the paintings that the visitors came to see in the first place. The caves at Lascaux in France have been affected by a different but similar problem. In those caves soil disturbance caused by building an air conditioning system has led to the growth of lichens and fungi infections which have proved hard to control. At both Altamira and Lascaux, replica caves have been built so that visitors can see what the cave paintings are like without entering the caves themselves. At Altamira, banning visitors from the real caves has stabilised the cave atmosphere; an international scientific commission has been established to investigate solutions to the problems at Lascaux.

'I don't mind not going in,' said Ralph, 'let's find an art class and draw our own llamas.' 'I can draw stick rabbits,' Flopsy said, 'I bet they'll attract crowds in 35,000 years.' Ralph repressed a smirk and trotted off to buy some crayons.

Answer: Titan

Speedwell is one of four show caves open to the public near Castleton in Derbyshire - the others are Peak Cavern, Blue John Cavern, and Treak Cliff Cavern. All these caverns are a mixture of natural caves and mines. Some shafts at Castleton have been known and used for centuries, others like Titan are more recent discoveries - Titan was found only in 1999 and its existence was not revealed until 2006. Titan is the deepest natural cave in Britain at 141.5 metres (464 feet); it is linked to another deep shaft 'Leviathan' which was used for lead mining in the eighteenth century if not earlier. Many of the caverns at Castleton are connected but some of them, such as Titan, have either been blocked over the years or were impassable before the development of modern caving equipment; Titan is still only accessible by abseiling.

As well as lead mining, caves at Castleton were mined for a semi-precious mineral known as Blue John, particularly the Blue John Cavern and Treak Cliff. Blue John is a rare form of blue-banded fluorite used for decorative purposes, e.g. for carved ornaments and jewellery, and is still mined in the two caverns in areas away from public view. Mining is restricted as Treak Cliff is classified as a Site of Special Scientific Interest because of the coloured stalactites found there.

The Peak District in central England is mainly, though not entirely, in the county of Derbyshire. To the east lies Nottinghamshire, home of the legends surrounding Robin Hood. One theory says that a previous name for Robin Hood was Robin Goodfellow who in turn was based on the legends of Puck, an English fairy or sprite known for his mischief-making. There's no connection however between Big John and Blue John.

'I know this area is called the Peak District,' said Ralph, 'but Peak Cavern sounds like a rather boring name.' Flopsy opened her book of holes in the ground and told Ralph that Peak Cavern was given its name in the nineteenth century because its traditional name was thought to be too offensive for Queen Victoria to hear when she attended a concert there. Many people still call it by its original name which has something to do with the Devil's anatomy, reflecting the rude noises made when flood water drains out of the cave... but if it was too rude for Queen Victoria, it's certainly too rude for FunTrivia so you'll have to look it up, Ralph. 'I can't do that,' said Ralph. 'Why not?' asked Flopsy, 'all the llamas can use computers if only vaguely.' Ralph looked plaintive. 'I would,' he said, 'but I'm stuck!'