31 votes

What are these undersea lines all around Hawaii?

Short answer: The lines radiating from the island are artifacts from a mapping process that superimposes high-resolution sonar data from standard ship tracks on top of r low- or average sonar data ...
jeffronicus's user avatar
  • 3,492
27 votes
Accepted

How old is the Earth?

Yes, the age of the Earth is about 4.5 billion years (4,500 million years). Your linked articles describes well how it was formed and how we know about it. The uncertainty is less than 1% and depends ...
user2821's user avatar
  • 5,946
26 votes
Accepted

Does the Plate tectonics contradict the theory of continental drift?

The boundary between the African and South American plate is a 'divergent' boundary. The two continents were joined as part of the Pangean super-continent. In the Cretaceous period a rift opened up ...
Andy M's user avatar
  • 2,057
24 votes
Accepted

What is the fastest the Earth has ever spun?

The speed of rotation of Earth is controlled by its angular momentum. And the conservation of angular momentum is a very serious law of physics (perhaps even stricter than conservation of mass). So in ...
Camilo Rada's user avatar
  • 17.7k
23 votes

Why had climate change not been proven beyond doubt for so long?

It's the first very significant report to make that claim because the claim is unscientific in nature. As Albert Einstein once said: The scientific theorist is not to be envied. For Nature, or more ...
TCooper's user avatar
  • 377
19 votes
Accepted

When did wildfires start to occur on earth?

A definitive statement comes from the abstract of Scott and Glasspool1, 2006: Charcoal, a proxy for fire, occurs in the fossil record from the Late Silurian (≈420 Myr) to the present. One of the ...
Spencer's user avatar
  • 3,558
18 votes

Does the Plate tectonics contradict the theory of continental drift?

Alfred Wegener developed his theory of continental drift in the early 20th century. His theory wasn't well accepted at that time. Geologists of that time had their own not quite scientific ideas ...
David Hammen's user avatar
  • 23.6k
17 votes
Accepted

Why had climate change not been proven beyond doubt for so long?

Chapter 9 of the Fourth Assessment Report gives a comprehensive overview of the difficulties involved in 'detection and attribution'. It is worth reading in detail - it gives a much better idea of the ...
Nullius in Verba's user avatar
16 votes

If we assume the mega impact hypothesis for the formation of Moon, where on Earth is the impact point?

I think you are confused about the timescales and the magnitude of the impact that is being talked about here. The collision between the early Earth and a roughly Mars sized body, Theia is thought to ...
bon's user avatar
  • 2,211
15 votes

What significant factors influencing geological change are still occurring?

The effects of Earth's past climate variations on the landscape, especially glaciation, cannot be underestimated. The multiple glacial advances and retreats over the last 4 million years or so have ...
Spencer's user avatar
  • 3,558
15 votes

Why had climate change not been proven beyond doubt for so long?

Just because a "small number" of scientists knew about something in the mid 1820s doesn't mean it was initially accepted by other scientists. You also have to consider the means of ...
Fred's user avatar
  • 24.7k
14 votes
Accepted

What would it be like to live in an ice age?

It depends where, the continental landmasses at higher latitudes would be covered by massive ice sheets. Therefore the life in the sections of the US and Europe that are close to the Ice sheets would ...
Camilo Rada's user avatar
  • 17.7k
14 votes

Could the earth be much older than the currently accepted number?

The age of the solar system is 4.6 billion years. We know that because almost all meteorites are 4.6 billion years old¹. Therefore, that puts a very solid upper boundary to the age of the Earth. ...
gerrit's user avatar
  • 11.7k
13 votes
Accepted

Water on Mars and Earth

If water on Earth came from meteorites, why doesn't Mars have substantial water? First off, that's a conjecture regarding the origin of the Earth's water rather than a known fact. A few times a year ...
David Hammen's user avatar
  • 23.6k
11 votes
Accepted

Is there likely to be coal under the Sahara?

The older rocks underlying the Sahara are mostly granite, schist, or gneiss, all mixtures of igneous and metamorphic rocks forged deep beneath the surface This stable mass of rock has been covered ...
Fred's user avatar
  • 24.7k
10 votes
Accepted

For how long has the Earth been habitable for humans?

One needs breathable air, drinkable water, and food to survive. Food as we know it was nonexistent prior to the Ediacaran, which began about 635 million years ago. Life was exceedingly primitive (...
David Hammen's user avatar
  • 23.6k
10 votes
Accepted

If Earth had rings would gravity exerted by Earth decrease?

Rings wouldn't decrease the gravity much, but the exact amount would depend on the exact geometry of the rings. One reason is that the gravity of one side of the ring would partially cancel the ...
Camilo Rada's user avatar
  • 17.7k
10 votes

What are these undersea lines all around Hawaii?

Hawai was created by a coat of plume. This means that hot material rises and penetrates the oceanic currents! These are fracture marks from this process. Secondly, the plate is torn apart by ...
Weiss's user avatar
  • 1,989
9 votes

Why is a future increase in solar luminosity by 10% supposed to have disastrous consequences for life on earth when the last 30% did not?

In this regard you can think that the Earth system is like a house with heating but no Air conditioning. Therefore, it has a powerful mechanism to stay warm when the solar illumination is weak (...
Camilo Rada's user avatar
  • 17.7k
9 votes

Does the Plate tectonics contradict the theory of continental drift?

"Continental Drift" was a theory developed to explain observed phenomena (the coastline of South America and Africa being but one example). Plate tectonics, on the other hand, is the ...
SoronelHaetir's user avatar
8 votes

What is the age of the earth's oil?

Oil can be generated from pretty much anything organic. The oldest oil that I know of comes from a porous Eocambrian siltstone in the Sultanate of Oman. This was formed nearly 200 million years before ...
Gordon Stanger's user avatar
8 votes

A circle shape in Madagascar

It is an extinct volcanic crater. The location is not listed as one of the active volcanoes in Madagascar. Simplified geologic map of Madagascar (reference) shows the crater to be mapped as basaltic /...
Earth Science Expatriate's user avatar
8 votes

Are we entering a new Ice Age according to Milankovitch cycles?

It thus seems reasonable to say we are entering another Ice Age according to Milankovitch cycles. Some of the Milankovitch conditions would appear to make the Earth ripe for a new glacial epoch ...
David Hammen's user avatar
  • 23.6k
7 votes

Why silicon is abundant in earth surface?

Silicon, in the form of silica (oxidised silicon: Si4+ or SiO2), is indeed very common on Earth's surface. This answer has two parts: why is silicon common in the Earth as a whole, and why it is ...
Gimelist's user avatar
  • 23.1k
7 votes

Is there any place on Earth that is permanently a desert?

UserLTK, above, has mentioned the Dry Valleys of Antarctica and the Atacama desert as two notable examples of "permanent" deserts. It's likely that these two locations have been deserts for at lease ...
Knob Scratcher's user avatar
7 votes

Was the Earth's sea-level significantly lower in ancient times?

There are several questions here, I'm only focusing on the question regarding sea level in the past as per the title question. In short, global mean sea level (GMSL) has been both lower and higher ...
Tom Newton's user avatar
7 votes
Accepted

Book on the history of Earth and life on Earth

Cowen's History of Life Your best bet is Cowen's History of Life, it is an excellent introductory textbooks for paleontology well laid out and clearly written with introductory students in mind so a ...
John's user avatar
  • 6,891
7 votes
Accepted

How has the total area of continents changed during the Earth history?

I think the question is asking about the trend, i.e., how did we get from zero continental crust to about 30 % over the Earth's history? Was it linear, another trend? Well, one figure is enough to ...
Jean-Marie Prival's user avatar
6 votes

What is the age of the earth's oil?

The previous answer is actually correct in stating that fish have very little to do with oil formation. Hydrocarbons of a volume that is able to accumulate a reservoir that is economic to produce ...
blaydes's user avatar
  • 121

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