How are white beaches created

Knowledge test: beaches

by Thomas Hess
Where does the sand on sandy beaches come from anyway? Why are there green beaches and where is the highest tide difference in the world? Test your knowledge of beaches!

The answers to the questions can be found below.

Question 1 of 13
Sandy beaches are basically small, ground mountains that have been washed into the sea and then deposited again. However, the white sand of tropical beaches is created differently. How?

a) The sand is created by volcanic eruptions below sea level

b) The sand is mostly - well - fish droppings

c) Certain silicates form in the warm water of tropical seas

Question 2 of 13
What makes surf currents (riptides) so dangerous?

a) Suddenly ice-cold water

b) A strong pull

c) They occur in connection with poisonous algae

Question 3 of 13
What is special about the Bay of Fundy in Nova Scotia, Canada?

a) A cliff made of pure marble

b) A permanent vortex near the beach

c) The highest tide difference in the world

Question 4 of 13
No tropical beach without coconut palms, which provide shade for lazy people and whose fruits give many cocktails the exotic taste. But coconuts have even more to offer. How did you rescue wounded soldiers during WWII?

a) By their antibiotic effect. Penicillin was not yet widely used

b) The coconut shells make perfect pressure bandages

c) Coconut water was given as an infusion

Question 5 of 13
It glows red, yellow, green and white on the beach at Fort Bragg, California. What is the reason?

a) The flowers of a salt-compatible ground cover

b) The beach is littered with glass

c) The flags of all 38 counties that made California

Question 6 of 13
Green is not exactly the color you would expect from a beach. Where does Papakolea Beach in Hawaii get its intense color from?

a) In the 1970s a tanker with green paint was stranded there

b) Volcanoes heat the water near the beach and cause algae to proliferate

c) The sand consists of olivine, a crystal

Question 7 of 13
254 km - which beach record does this number belong to?

a) To the longest beach in the world

b) To the widest beach in the world at low tide

c) To the windiest beach in the world

Question 8 of 13
Coarse sand, fine sand or pebbles - beaches consist of different materials. But what decides whether you can walk on gravel or fine sand on the beach?

a) The wave height on the coast

b) The water temperature

c) The slope of the sea floor

Question 9 of 13
Why are footprints briefly dry in the sandy fringes of the floodplain?

a) The body pressure warms the sand suddenly - you blow dry it, so to speak

b) The pressure tears holes in the sand structure - it simply runs out

c) The pressure squeezes out the sand like a sponge

Question 10 of 13
Under what conditions does sand such as Sieasta Beach in Florida squeak under your feet?

a) It must be extremely fine

b) It must contain the fat of a certain type of algae

c) The sand grains must be almost spherical

Question 11 of 13
Why do visitors to the "Hot Water Bay" near Coromandel in New Zealand dig hollows in the sand at low tide?

a) You want to boil eggs

b) You build yourself a kind of natural spa with warm water

c) They do laundry. Certain salts in the water are the perfect eco-detergent

Question 12 of 13
Where did California's beach bowling ball get its name from?

a) Rock formations on the beach look like XXL bowling pins

b) The sand is firm and absolutely smooth - the perfect bowling alley

c) Huge stone balls are lined up on the beach

Question 13 of 13
What is Praia do Norte beach in Nazare, Portugal famous for?

a) For gigantic waves

b) For ideal windsurfing conditions

c) For extensive oyster beds

Attention resolution!

Here are the answers to the review:

Question 1 of 13
Sandy beaches are basically small, ground mountains that have been washed into the sea and then deposited again. However, the white sand of tropical beaches is created differently. How?

a) The sand is formed during volcanic eruptions below sea level ❌

b) The sand is mostly - well - fish droppings ✔️

c) Certain silicates ❌ form in the warm water of tropical seas

The sand of most tropical beaches is made up of finely ground corals and shells. Parrotfish are keen on certain algae that grow on the corals. The fish scrape off the corals with their "beaks" or gnaw them right away. The fish swallow the algae-coral mix, the excrement consists almost of pure coral crumbs, which are then deposited as sand.

Question 2 of 13
What makes surf currents (riptides) so dangerous?

a) Suddenly ice-cold water ❌

b) A strong pull ✔️

c) They occur in connection with poisonous algae ❌

Surf back currents arise where the surf water cannot flow back into the sea unhindered and is bundled, for example, at gaps between sandbanks, creating a suction out into the sea. The currents are usually only a few meters wide, but very strong. If you get in there, you should swim parallel to the beach until you are out of the current. Surf currents can often be recognized by a plume of sand in the water leading into the sea.

Question 3 of 13
What is special about the Bay of Fundy in Nova Scotia, Canada?

a) A cliff made of pure marble ❌

b) A permanent vortex near the beach ❌

c) The highest tide difference in the world ✔️

In the Bay of Fundy between Nova Scotia and New Brunswick in North America, the water level drops a full 15 meters at low tide, 100 million tons of water rush out of the bay within six hours, and the ebb tide is like a raging river.

Question 4 of 13
No tropical beach without coconut palms, which provide shade for lazy people and whose fruits give many cocktails the exotic taste. But coconuts have even more to offer. How did you rescue wounded soldiers during WWII?

a) By their antibiotic effect. Penicillin was not yet widely available ❌

b) The coconut shells make perfect pressure bandages ❌

c) Coconut water was given as an infusion ✔️

The wounded were given coconut water as a blood plasma substitute. On the one hand, because coconut water has roughly the same salt and nutrient content as real blood plasma, and on the other hand, because coconut water is absolutely sterile.

Question 5 of 13
It glows red, yellow, green and white on the beach at Fort Bragg, California. What is the reason?

a) The flowers of a salt-compatible ground cover ❌

b) The beach is littered with glass ✔️

c) The flags of all 38 counties that made California ❌

The beach near San Francisco is littered with hundreds of thousands of glass pebbles, which is why it is also called "glass beach". The stand used to be a garbage dump, where glass was also disposed of. Over time, the waves have polished the broken pieces and dumped them on the beach

Question 6 of 13
Green is not exactly the color you would expect from a beach. Where does Papakolea Beach in Hawaii get its intense color from?

a) In the 1970s a tanker with green paint was stranded there ❌

b) Volcanoes heat the water near the beach and let algae grow ❌

c) The sand consists of olivine, a crystal ✔️

Olivine is of volcanic origin and is green, sometimes almost brown, in color.

Question 7 of 13
254 km - which beach record does this number belong to?

a) To the longest beach in the world ✔️

b) To the widest beach in the world at low tide ❌

c) To the windiest beach in the world ❌

The Praia do Cassino in Brazil runs from Molhes da Barra to the Uruguayan border. A walk on the beach quickly turns into a multi-day hiking tour!

Question 8 of 13
Coarse sand, fine sand or pebbles - beaches consist of different materials. But what decides whether you can walk on gravel or fine sand on the beach?

a) The wave height on the coast ❌

b) The water temperature ❌

c) The slope of the sea floor ✔️

The shallower the seabed near the shore, the finer the stones that can be deposited. Therefore, you can often go far into the sea on sandy beaches.

Question 9 of 13
Why are footprints briefly dry in the sandy fringes of the floodplain?

a) The body pressure heats the sand suddenly - you blow dry it, so to speak ❌

b) The pressure tears holes in the sand structure - it simply runs out ✔️

c) The pressure squeezes out the sand like a sponge ❌

Soaked sand has the maximum possible sand grain density and few gaps: in wet sand, grains of sand are arranged extremely close to one another, the water acts like a lubricant, so that the grains come close to the skin. Small gaps always remain, however, as the irregular grains do not fit together exactly. If you step on the sand, the closely interlocked grains give the pressure a few layers deeper not only downwards, but also to the laterally located grains, the dense sand packing tears open, the gaps become larger and fill with water from the surface.

Question 10 of 13
Under what conditions does sand such as Sieasta Beach in Florida squeak under your feet?

a) It has to be extremely fine ✔️

b) It must contain the fat of a certain type of algae ❌

c) The grains of sand must be almost spherical ❌

The fine grain is an essential requirement for squeaky sand. Siesta Beach has powder-fine sand made of 99.99 quartz that squeaks under your feet and stays pleasantly cool in the heat.

Question 11 of 13
Why do visitors to "Hot Water Bay" near Coromandel in New Zealand dig hollows in the sand at low tide?

a) You want to boil eggs ❌

b) You build yourself a kind of natural spa with hot water ✔️

c) They do laundry. Certain salts in the water are the perfect eco-detergent ❌

As a relic of earlier volcanoes, the rock layers 2 km below the beach are a good 150 ° C and heat the groundwater. Only during low tide are stretches of beach exposed where warm water reaches the surface. Shovels for digging are rented right on the beach!

Question 12 of 13
Where did California's beach bowling ball get its name from?

a) Rock formations on the beach look like XXL bowling pins ❌

b) The sand is firm and absolutely smooth - the perfect bowling alley ❌

c) Huge stone balls are lined up on the beach ✔️

The balls, on average one meter in size, are made of sandstone and are exposed by the sea, wind and rain from the cliffs on the beach until they roll over the beach and stay there. You can see the balls at low tide.

Question 13 of 13
What is Praia do Norte beach in Nazare, Portugal famous for?

a) For gigantic waves ✔️

b) For ideal windsurfing conditions ❌

c) For extensive oyster beds ❌

The professional shore Garrett McNamara has there on January 28th. Rode a wave a good 30 m high in 2013. The seabed in front of the beach offers ideal conditions for giant waves.

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