Tag: land

The Increasing Land Area of Finland

By Anupum Pant

Tectonic plates float at a certain elevation on Earth. This elevation is decided by what lies on the plate. So, depending on the density and thickness of the matter that is present on a tectonic plate, the plate adjusts its elevation to maintain a gravitational equilibrium between the uppermost solid mantle and the mechanically weak layer – Asthenosphere – which lies just below it. This is call Isostasy.

During the Ice age when the land masses were covered in ice sheets up to 3 kilometres thick, the landmasses got depressed. This was about 20,000 years ago (last part of the last ice age) when the massive ice weight made the mechanically weak mantle below the solid mantle, deform. Under pressure, the semi-solid-ish mantle below, started flowing to other places where the solid mantle was higher and allowed a greater place for the ductiley flowing mantle below the plates.

When this period ended, the glaciers started retreating and the landmasses started rising from depression. Now, since the mantle below is not totally liquid, it took a lot of time for it to rush back into place from where it was displaced by the primitive heavy ice covered land. In fact, at some places on Earth, this rebound is still happening – This is known as the post glacial rebound.

This can be seen in some parts of Finland, where the land around the Gulf of Bothnia rises about 1 cm each year to maintain the gravitational equilibrium between the Lithosphere (solid mass) and the Asthenosphere (the semi-solid-ish stuff below the solid mass)! As a result the land which was previously below sea, rises upwards and Finland expands in area – about 7 Square kilometres annually. This rise has been recorded by the BIFROST GPS network. And is estimated to continue for the next 10,000 years, not necessarily at the same rate.

via [Post Glacial rebound]

Is Cheetah No Longer the Fastest Land Animal?

By Anupum Pant

Read this for the answer to the question above

If you haven’t previously heard of the Betteridge’s law of headlines, also known as the Davis’ law or the journalistic principle, here’s what it says:

Any headline which ends in a question mark can be answered by the word no.

(Of course, you aren’t supposed to take the “law” too seriously.)

Did you see the headline for this article? So, basically you can read no further and still say – No, Cheetah still is the fastest land animal. But if you look deeper, things sure get interesting.

Absolute Speed vs. Relative Speed

To be specific, Cheetah is the fastest land animal because its absolute speed on land is the highest (112 to 120 Km per hour). When you measure absolute speed, you don’t take into account anything other than the speed. The weight or size of the animal doesn’t matter. Here, Cheetah is a clear winner.

But, when you do take into account the body length of an animal and measure the speed in terms of, number of body lengths the animal can cover in a single second, there are number of other animals that beat Cheetah by a huge margin.

Here’s a fact – When running at full speed, cheetahs can cover the length of up to 16 to 20 cheetahs in a single second. That’s pretty fast. The fastest humans on earth can do about 10 – 11 body lengths per second. [Source] Do you know what’s the fastest animal of you measure speed relative to their respective body lengths? Wait for it…

It is a mite. Yes, a tiny little 1-2 mm Californian blood sucker can cover up to 322 body lengths in a single second! Scientists just found out about it. Graphic designers who’ve used elegant cheetah silhouettes to represent speed in their graphics will have to use a tiny blood sucker now? How disappointing!

By the way, 322 body lengths in a single second of a sesame sized animal translates to just about 0.8 km per hour of absolute speed. But, imagine this. If it (the Californian mite) were the size of a human being (which it is not), it would have moved at a whopping 2,100 km per hour. I know the physics of it would have been different in case it were that big. Since it is not, we aren’t even putting in the effort to consider those details at the moment.

In case someone comes searching for the scientific name of this mite, it is called – Paratarsotomus macropalpis (I won’t remember that)

Other land animals “faster” than the Cheetah

  • The Australian tiger beetle held the record before they found out about the tiny mite. The beetle can cover up to 171 body lengths in a single second.
  • The household cockroach is pretty fast too. It does about 50 body lengths in a single second.
  • The ghost crab can run at about 100 body lengths per second.

All of them, much “faster” than the cheetah (in relative speed). And still Cheetah always wins the race because it is absolutely the fastest land animal. Still. Please don’t trust the click bait titles like:

Cheetah beaten to title of fastest animal in the world by tiny Californian mite

Pacific Leaping Blenny – Fish Lives on Land

By Anupum Pant

Scientific name: Alticus arnoldorum

After having seen animals that live on for centuries, fish that have legs and several others, another fascinating animal joins the list at AweSci today. The Pacific Leaping Blenny – A fish that, unlike every other extant specie of fish, lives on land.

Wait! What?

The Pacific Leaping Blenny is a 2-4 inches long fish that is found on reefs in Samoa, Marianas, Society, and Cook Islands, in the western and southern Pacific Ocean. For all its life, this fish stays on land. It breathes through its gills and partly through its skin.

During the few hours when the tide is at a normal level, such that the waves are just strong enough to reach them and not enough to pull them back into water, these fish take care of their business on land. They need the water to hit them because it keeps their skin wet. Which in turn, lets them breathe through their gills and skin. As long as their skin is moist, they can live out of water indefinitely. So much that they have been officially classified as a terrestrial specie. They would suffocate if their skin dries off completely.

Their fascinating camouflage

It is fascinating to see an existing example of how ancient sea dwelling creatures must have first evolved. At these times when we have great predators waiting on land to immediately end this transitional specie, this fish does a great job of hiding itself from them. And given their poor speed on land, that is how they survive on these rocky shores. They have developed a specialized kind of camouflage that makes it difficult for a predator to find and kill them. As you can see in the picture above, they have a skin color that matches very well with the surrounding reefs/rocks.

How do they move on land?

Since they don’t have legs, that is exactly the question that hit my mind when I first read about these creatures. Turns out, for movement on land, they have developed a very peculiar kind of a movement style. They twist their tails, load up the tension and then release to leap. This sequence happens too quickly to notice easily through naked eyes. So, picked off directly from the Wikipedia page, here we have a slow motion video of this fish leaping off.

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