Questions tagged [earth-history]

Questions relating to Historical Geology.

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Water and Atmospheric Conditions in Earth prehistory

I pose this question as a curious enthusiast lacking formal education in chemistry or Earth sciences. My intrigue has been kindled by various articles and discussions and while I may not be certain of ...
user51552's user avatar
3 votes
2 answers
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When the Earth was hit by a meteor in Jurassic era, did it change its orbit or not?

When the Earth was hit by a meteor in Jurassic era, did it change its orbit or not? Here is a National Geograpic video about the event: https://www.youtube.com/watch?v=dNRTtLLuNM8
João Carlos Maximiano's user avatar
3 votes
1 answer
94 views

How did "dust and gas" form into the Hadean Earth?

We understand that the Hadean Earth was basically a giant ball of magma, constantly bombarded, no atmosphere, and solidified material never accumulated as Earth was too hot at its surface. We know ...
BigRigz's user avatar
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Interpretation of Phanerozoic CO2 levels graph

I used to talk with a family friend who often sent me links to Nobel Prize winners, claiming that climate change is a myth. Last week, we had a disagreement over a link referencing a Nobel Prize ...
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iron of the core of earth [duplicate]

@ralhecman:so why scientists say that the core of the earth is melted Iron, how that happens? if they also say that iron is the result of a dead start, and what about the other planets in the solar ...
Hector Ramon's user avatar
3 votes
1 answer
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If the universe (and our galaxy) has about twice as many oxygen atoms as carbon ones, why does Earth have 300 times as many oxygen atoms as carbon?

A (relatively) recent 'Sky & Telescope' magazine feature story mentioned how little carbon the Earth has, and how some scientists' models predict we should somehow have even less.... So I looked ...
Kurt Hikes's user avatar
2 votes
1 answer
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Impact Erosion Selectivity In Offloading Radioactive Material

ref : https://science.ubc.ca/news/asteroid-impact-erosion-helped-make-earth-habitable According to the theory of impact erosion, the early crust was presumably much hotter w/ radioactive isotopes (U &...
theRiley's user avatar
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How important or necessary are assumptions when it comes to radiometric dating?

So when I say radiometric dating, I'm specifically referring to U-Pb, Ar-K and Rb-SR rather than C14 as I think these are more accurate when it comes to corroborating an older earth. I've heard people ...
Mihir Dhawan's user avatar
8 votes
0 answers
62 views

Was the Earth a lot foggier millions of years ago?

Quoting a sign in Redwood National Park: Redwoods once covered large expanses of the world. Millions of years ago some of these redwoods were preserved as fossilized trees when volcanic ash buried ...
neubert's user avatar
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Spectrum of tilt motion of earth axis

The Earth axis changes tilt with a period of 41 000 years, and with an amplitude of 1.2 degrees. What does the spectrum look like? Is it a steady periodic motion, or rather some quasi-periodic ...
user877329's user avatar
1 vote
1 answer
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Does granite and basalt behave differently in different atmospheric pressures?

We all know that the oxygen levels increase and decrease as well as the temperature, so I believe it's safe to assume atmospheric pressure changes as well... And since granite and basalt are formed ...
American woman's user avatar
10 votes
2 answers
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How has the total area of continents changed during the Earth history?

Earth's total land area has increased throughout its history according to this video. What is the dependence of the total area of continents from time?
Imyaf's user avatar
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How have Schumann resonances varied in previous eras and periods on Earth?

Schumann resonances vary with losses in the cavity between Earth and the ionosphere and variability of the upper boundary due to atmospheric conductivity and ionospheric dynamics: BALSER, M., WAGNER, ...
David Jonsson's user avatar
2 votes
0 answers
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Why the reversed-order terminology for paleocene/eocene and eoarchean/paleoarchean?

I just learned that the eoarchean era comes right before the paleoarchean era, whereas the paleocene epoch comes right before the eocene epoch. This is quite confusing. Is there any sense behind this (...
WillG's user avatar
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Could a great diamond deposit have been derived from the Theia event?

If the Theia event was true, could it have formed a great deposit of diamonds out of the impact?? If that was the case, is it correct to suppose that somewhere hidden within the surface of the Earth ...
Raul Luna's user avatar
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What would East Anglia look like without the presence of humans today?

I am interested in the native landscape of the UK before humans starting ploughing the earth, introducing livestock and deforesting. What would someone see walking from say the location of Cambridge ...
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Did the Vredefort Crater fill in soon after impact?

The Vredefort Crater is said to have been 40km deep and 100km wide. But what I'm curious about, is how long it retained that shape. Would magma have immediately leaked into it and filled it, for ...
user27657's user avatar
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5 answers
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Why had climate change not been proven beyond doubt for so long?

I just read the IPCC's Fourth Assessment Report and noticed that this is the first (or first very significant) report to state that climate change exists and can no longer be scientifically disproved. ...
Weiss's user avatar
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What is the size of Earth's biomass over time? How has it changed? [duplicate]

I've seen this question asked before and the answer was we don't know because of the poor fossil record. I'm unsatisfied with that as it seems that other means like sedimentation might be a starting ...
Tom Hite's user avatar
26 votes
2 answers
5k views

What are these undersea lines all around Hawaii?

On Google Earth, there are these radiating undersea lines all around Hawaii: Here with a bit more contrast: Unlike the other lines, they are pointed away (or toward) a single place. What are these, ...
2080's user avatar
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Time of day of Chicxulub impact

Is there any known evidence about what the local time of day of the Chicxulub impact was (at the very least, whether the impactor struck during day or night)? If there is not any such known evidence, ...
SeekingAnswers's user avatar
3 votes
1 answer
164 views

Countering climate change skeptics that point to previous warming episodes

If the question is a bit confusing, what I'm asking is if there is scientific evidence to counter an argument against climate change that I had come across. The person said that climate change is not ...
Seraphim's user avatar
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7 votes
1 answer
785 views

Is there likely to be coal under the Sahara?

In Pangaea, northern Africa would have had humid onshore winds from the Tethys Ocean, making dense vegetation/rainforest biome likely. Consequently, would we be likely to find coal underneath the ...
Miner_Glitch's user avatar
7 votes
4 answers
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Does the Plate tectonics contradict the theory of continental drift?

According to the theory of continental drift, South America and Africa was so closed to each other that the convex triangle of South America meets the concave hollow of Africa. Source: usgs.gov; ...
Michael's user avatar
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When did mosquitoes reach Australia?

When and how did mosquitoes reach Australia? It's east of the Wallace line, so 'they got there from Asia' is not an obviously unproblematic conclusion. In general, when and how mosquitoes reached ...
rwallace's user avatar
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2 votes
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Variability in 4.5 billion year age of earth based on radioactive dating of meteorites?

Which meteorites in particular give an age of 4.5 billion years and which isotopes are used for radioactive analysis? Is there much variability if different meteorites or isotopes are used?
mr_js's user avatar
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3 answers
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What methods/apparatus are used to model the early Earth? What do we know of their accuracy?

A friend of mine asked our teacher but the class was over and in online mode, I can't ask my teacher until the next lecture. It sparked my curiosity, I know we use carbon dating for finding the age of ...
gagan's user avatar
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1 answer
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Where to find graphite rocks? [closed]

Where to find graphite rocks? I made researches in my city beach but I don't know where to find them.
user24547's user avatar
5 votes
0 answers
125 views

Why did the Tigris and Euphrates but not the Nile river basins experience desertification?

The sites of ancient Mesopotamian civilizations tend to be very dry, unlike those of ancient Egypt. Looking at the areas via online maps also shows, that while the Nile river basin remains very green, ...
TheChymera's user avatar
9 votes
4 answers
2k views

What significant factors influencing geological change are still occurring?

I am teaching a secondary school course on my state's local history. The textbook begins with the history of the first humans, yet I think it is unfair not to start back much earlier, introducing the ...
Village's user avatar
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Is there any source that shows all of Earth's terrain changes from Pangea to present?

I teach a class on my state's history to middle school students. Our textbooks do not cover much historical geology, but its a subject students are fascinated in, and feel needs to be added. I want to ...
Village's user avatar
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3 votes
1 answer
155 views

Why are the south, the west and the north of the Caspian sea lush but its east completely dry?

About the Caspian sea area today: The south is very lush with the subtropical forests of the Iranian provinces of Gilan, Mazandaran and Golestan (although less "tropical" in Golestan) The ...
timesharer's user avatar
1 vote
0 answers
51 views

puzzling statement on earth history!

A Geology proffessor recently told me that around 200,000 years ago, when homo sapiens emerged, that "...all of civilisation can now fit on the width of a single strand of human hair." I am ...
Jonathan's user avatar
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2 votes
1 answer
273 views

What was the oxygen concentration in the air during the late miocene period?

As the title says, I'd like to know what the O2 concentration was during the late Miocene period. I've tried to look this up but I'm having a hard time finding any conclusive data on it, or even any ...
micah's user avatar
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1 vote
1 answer
56 views

Would it be possible, from the earth’s creation or during its various geomorphological changes, for all the following hypotheses to be probable?

I’m designing a fictional world setting for a game, and I would like to know whether it has a relative coherence based on science. (Don’t mind if it is an almost improbable scenario). Would it be ...
Spyros's user avatar
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1 vote
2 answers
92 views

Solution for the coexistence of overpopulated human species with nature [closed]

Is there any solution to deal with the overpopulation of our species at the same time protect the natural environment of ours? (other than finding a inhabitable planet?)
VGB's user avatar
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4 votes
1 answer
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Has Earth's geological activity calmed down in the past 250 million years?

In the past, the Earth's ecosystem has experienced catastrophic mass extinctions as a result of large-scale volcanic eruptions. One example is the event known as the "Great Dying", 252 ...
Peter - Reinstate Monica's user avatar
6 votes
1 answer
184 views

Book on the history of Earth and life on Earth

I am interested in getting a better overview of the full history of the Earth and the evolution of life. Therefore I am looking for a book that goes through the different geological time scales of the ...
The One's user avatar
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4 votes
1 answer
172 views

How far would average sea level rise from a 25% increase in total ocean volume?

What amount of average sea level rise (in meters above 2020 levels) would be associated with a 25% increase in total ocean volume? The reason I ask is because of this study that indicates Earth has ...
CommaToast's user avatar
4 votes
2 answers
1k views

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

Milankovitch cycles consist of three orbital parameters: eccentricity, obliquity, and precession of equinoxes. According to Milutin Milankovitch, the most recent glacial period ended nearly 11,000 ...
seamos's user avatar
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5 votes
1 answer
266 views

How much of the petroleum ever formed has made it into reservoir rocks?

I am aware that it's a bit general a question, and petroleum geology (or petrology ;-)) has never been a field of interest to me. A superficial search using related keywords brings up only economic ...
user avatar
2 votes
0 answers
88 views

What do scientists mean when they say the Earth formed 4.56 billion years ago? [duplicate]

Does that mean that the Earth gained the classification of a planet that long ago rather than some other celestial body? How did they determine that this happened that long ago? How discrete is the ...
RandallSmith's user avatar
4 votes
1 answer
946 views

Geo-Spherical shape of Earth

I know that the best possible approximation of the shape of earth is an oblate sphere. But people also call it as geo-spherical shape of the Earth. What is the meaning of geospherical shape? Does this ...
Talha khan's user avatar
3 votes
0 answers
98 views

What were the Two Largest Forests of Western and Central Europe (circa 600 BC)

I am trying to find out what forests were the largest in Western and Central Europe, around 600 BC. I understand that accounts dating that far back may be difficult to find, but I hope other sciences ...
user20379's user avatar
6 votes
1 answer
165 views

Has a scientific consensus been reached concerning the formation of the Grand Canyon?

new student of Oceanography here! I'm studying Earth Science right now, and I found conflicting reporting re: the formation of the Grand Canyon; whether it was formed singularly by the Colorado ...
DanielC's user avatar
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1 vote
2 answers
309 views

How was the onset of the Cambrian period dated?

What dating method was used to determine the beginning of the Cambrian, and what was its margin of error? Was only one fossil dated, or were a number of similar fossils used?
Michael Walsby's user avatar
1 vote
0 answers
102 views

Earth-like conditions on Titan: is it feasible that Titan once had seas and lakes of liquid water?

Given that: 1) Four billion years ago Saturn was hotter and radiated strongly in the infra-red. . . . . . . . . . 2) Like Earth's moon, Titan was then closer to its planet. . . . . . . . . . 3) Like ...
Michael Walsby's user avatar
3 votes
3 answers
305 views

How many days has it been since the Cambrian explosion?

I want to know how to calculate the number of days since an event in Earth's past, and am using the Cambrian explosion as an example. I define a day to be one rotation of Earth with respect to the ...
Perry Ainsworth's user avatar
2 votes
2 answers
242 views

What has been the influence of the moon on Earth's temperature?

What proportion of Earth's internal heat is generated by tidal flexion as a result of the orbiting moon, and would it have been significantly greater four billion years ago when the moon was closer? ...
Michael Walsby's user avatar
10 votes
1 answer
361 views

How quickly is the Earth shrinking?

Except for ice, acetic acid, bismuth and gallium and a few other things materials generally shrink when they cool and solidify, so I'm pretty sure Earth has as well. It probably wouldn't be ...
uhoh's user avatar
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