1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lyudmila [28]
3 years ago
11

True Or False? the total amount of matter on earth changes significantly over geological time scales, roughly every 300,000,000

years.

Biology
1 answer:
zaharov [31]3 years ago
3 0

The rate of atmospheric CO2 has never been as low as today and the temperature / CO2 content relationship is still poorly understood Since the Earth existed, that is to say 4.567 billion years ago [1 ], if it is indeed a constant is that it never remained fixed as it was, and that it was constantly deeply modified in a rather random way. This concerns as much the internal processes (in particular the composition of the lithosphere and the variations of the mechanisms affecting the continental drift) as the external processes

Among the latter, the atmosphere has not ceased to vary completely, particularly with regard to its gaseous composition. All of these internal and external processes have continually 'telescoped' and have led to complex feedbacks at the root of the many climate changes observed in the geological record. To these parameters are also added those piloted at the extraterrestrial scale, among the most important are the activity of the Sun or the variations of the orbital parameters of our Planet (precession, obliquity, ecliptic). The result is an extremely complex combination of regular cumulative processes, irregular, linear or not, often chaotic, playing at all time scales and affecting at any time the climate that constitutes an answer. Physicists, chemists, biologists, geographers ... geologists try each one from his pre-square to unravel this skein particularly difficult to understand. The synergies between the disciplines are fortunately numerous and the climate system is gradually exposed through the geological time.

L'étude du climat actuel semble plus simple que celle des paléoclimats, il s'agit cependant également d'une situation complexe vu l'importance des paramètres mesurables et mesurés qui contribuent à établir la dynamique de notre atmosphère aujourd'hui. L'étude de l'atmosphère est donc bien un des points incontournables pour qui veut comprendre un système climatique, elle est en prise directe avec la partie interne de la Terre (exemple des volcans, de l'érosion continentale suite aux orogenèses ou formations des chaînes de montagnes…), avec la partie externe ou superficielle (exemple des océans, des forêts…) et la composante extraterrestre (exemple des flux des rayons galactiques cosmiques, des impacts de météorites …). Nombre de ces paramètres sont cernés de manière satisfaisante depuis que la Terre existe. Cette connaissance débute avec le modèle du ‘paradoxe du Soleil froid' ou hypothèse astronomique du Soleil pâle[2].

Les premières atmosphères, des réservoirs de gaz à effet de serre

Ce modèle d'évolution du Soleil prédit que sa luminosité était plus faible de 25 à 30% de l'Hadéen à l'Archéen, soit d'environ 4,6 à 4,0 Ga (Ga = milliards d'années). Si l'on considère que la Terre possédait durant cette période une atmosphère semblable à la nôtre il faudrait alors attendre 2 milliards d'années (donc jusqu'au début du Paléoprotérozoïque) pour que sa température de surface dépasse 0°C, la température initiale à 4,6 Ga étant comprise entre -43 et -23°C suivant le modèle du ‘paradoxe du Soleil froid'. La quasi-totalité des océans aurait dû être couverte de glace. Les géologues n'ont jamais relevé de trace de glaciation globale durant cette longue période excepté quelques glaciers locaux à 2,9 Ga (glaciation ‘pongolienne') et à 2,4 Ga (glaciation huronienne). Ils concluent bien au contraire à une période chaude comme en témoignent notamment la présence de cyanobactéries à 3,8 Ga[3] et d'un cycle érosif de l'eau déjà actif ayant mené à l'accumulation de petits cristaux de zircon il y a 4,4 Ga[4]. L'eau était donc déjà présente 160 Ma (= millions d'années) après la formation de la Terre et les températures océaniques déduites des isotopes de l'oxygène et du silicium mesurés sur des roches siliceuses variaient entre 30 à 50°C (Archéen et Paléoprotérozoïque) bien loin d'un climat qui aurait du être globalement très froid comme le laisserait supposer un ‘Soleil pâle' de faible luminosité.

You might be interested in
Ozone in the troposphere is necessary to protect Earth's surface from harmful UV radiation.
romanna [79]

Answer:

False

Explanation:

In the troposphere, near the Earth's surface, human activities lead to ozone concentrations several times higher than the natural background level. Too much of this ground-level ozone is 'bad' as it is harmful to breathe and also damages vegetation.

The stratosphere or “good” ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays.

7 0
2 years ago
Warm-Up
bija089 [108]

Answer:

<u>Renewable Resources</u>

water

wind

geothermal energy

solar energy

<u>Nonrenewable resources</u>

minerals

fossil fuels

Hope this helps you

7 0
3 years ago
List the events of inspiration beginning with stimulation of the phrenic nerves
Andru [333]
The events of inspiration begins with the;
Impulses are conducted on the phrenic nerve to muscle fibers in the diaphragm contracting them.
As the dome shaped diaphragm moves downward the thoracic cavity expands.
At the same time the external intercostal muscles may contract raising the ribs and expanding the thoracic cavity further.
The intra-alveolar pressure decreases 
Atmospheric pressure greater than intra-alveolar pressure forces the air into the respiratory tract through the air passages.
The lungs fill with air.
3 0
3 years ago
Products enter a reaction and reactants come out of a reaction true or false?
hjlf

Answer:

\boxed {\boxed {\sf False }}

Explanation:

In a chemical reaction, the <u>produc</u>ts are <u>produc</u>ed. The <em>react</em>ants are the substances that <em>react.</em>

<em />

In a chemical reaction equation (with the arrow pointing right) the reactants are on the left and the products on the right.

  • reactants \rightarrow products

The reactants enter and the products come out.

So, the statement given - products enter a reaction and reactants come out - is false and it is actually the other way around.

3 0
2 years ago
Which animals are ectothermic? turtles and lizards birds and mammals frogs and mammals lizards and birds?
PilotLPTM [1.2K]
Ectothermic animals are cold blooded animals, or fishes, amphibians, reptiles, and invertebrates. So the right answer would be turtles and lizards. If the answer choices was supposed to look like this
turtles and lizards
birds and mammals
frogs and mammals
lizards and birds
It would be the first option.
Hope this helps!
4 0
3 years ago
Read 2 more answers
Other questions:
  • Fibers exiting the sympathetic chain ganglia, take one of three routes: the spinal nerve route, the sympathetic nerve route, and
    12·1 answer
  • In a publishable table format, present your plating results. include expected results and observed results columns in your table
    9·1 answer
  • What Is The Function of The Digestive System?
    14·1 answer
  • All macromolecules are made mostly of the same six elements. What are those six elements?
    10·1 answer
  • Which process MUST occur before mitosis and meiosis can occur?
    14·1 answer
  • Which is usually true of Archaea?
    14·1 answer
  • I need an example of how cancer relates to the cell cycle.
    15·1 answer
  • Why is it important to be able to date fossils?
    12·2 answers
  • ". Students were asked to illustrate their knowledge of forces that affect motion in plants.
    10·1 answer
  • C) .....are used to add the minerals in soil.​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!