Earth Science 1.1

What is Earth Science?

Earth Science 1.1 What is Earth Science?

○ Ear th Sc ienc e i s t he name g i ven t o g roup o f sc iences t ha t dea l s w i t h ea r t h and t he ne ighbo r ing bod ies i n ou r so la r sys tem.

○ Ear th Sc ience i nc ludes , among o the rsG e o l o g y

O c e a n o g r a p h y

M e t e o r o l o g y

A s t r o n o m y

Geology

Geology means “study of the Earth”

Geology is divided into two areas

Physical geology

Historical geology

Physical Geology

Physical geology inc ludes the examinat ion of the mater ia ls that makeup Earth and the possib le explanat ions for the many processes that shape our p lanet

Understanding the or ig ins of rocks and minera ls is an important par t o f physica l geology

Historical Geology Histor ica l geology’s a im is to

understand the Earth ’s long h is tory of these processes.

Histor ica l geology is concerned wi th establ ish ing t imel ines of the vast amount of changes, both physical and b io logical , that have occurred on the Earth over the course of t ime.

Oceanography Oceanography in tegrates the

sc iences of chemist ry, physics geology and b io logy to s tudy the composi t ion and movements of seawater, as wel l as coasta l processes, seaf loor topography, and mar ine l i fe .

Meteorology Meteorology is the sc ient i f ic s tudy

of the atmosphere and the processes that produce weather and c l imate

Like oceanography, meteorology a lso involves many other branches of sc ience

Astronomy Ast ronomy i s the s tudy o f the Un ive rse

wh ich inc ludes ear th ’s pos i t i on i n re la t i on to the Un ive rse .

The sc ience o f as t ronomy i s use fu l i n p rob ing the o r ig ins o f ou r env i ronment

Al l ob jec ts i n space , i nc lud ing ear th , a re bound by the laws o f phys i cs . Learn ing abou t o the r ob jec ts i n ou r so la r sys tem and the un ive rse he lps us to unders tand the Ear th

Earth Science

Together these sciences interact to provide us wi th a c learer snapshot of the Earth

GeologyOceanographyMeteorologyAstronomy

Formation of the Earth

Nebular hypothesisThe nebular hypothesis

suggests that the bodies of our solar system evolved from an enormous rotating cloud called a solar nebula.

The Nebu la r Hypothes is c la ims tha t 5 b i l l i on years ago , fo r reasons unknown, a huge nebu la r c loud began to con t rac t under i t s own grav i ta t iona l in f luence . As i t con t rac ted i t a lso had some ro ta t iona l mot ion .

The more i t con t rac ted the fas te r the c loud ro ta ted , caus ing the nebu la r c loud to take on a d isk shape. As the c loud co l lapsed , the tempera tu re o f the cen t ra l mass con t inued to inc rease and mos t o f the mater ia l was g rav i ta t iona l l y pu l led toward the cen te r, p roduc ing the Sun.

However, because o f the ro ta t iona l mot ion , some dus t and gases remained o rb i t ing the Sun. As these f ragments began to condense and co l l ide , they jo ined toge ther in to la rger ob jec ts wh ich even tua l l y became the p lane ts wh ich con t inued to o rb i t t he Sun .

Nebular Hypothesis

H i g h t e m p e r a t u r e s a n d w e a k g r a v i t y c h a r a c t e r i z e d t h e i n n e r p l a n e t s . A s a r e s u l t , t h e i n n e r p l a n e t s w e r e n o t a b l e t o h o l d o n t h e l i g h t e r g a s e s o f t h e n e b u l a r c l o u d .

T h e l i g h t e r g a s e s w e r e w h i s k e d a w a y t o w a r d t h e h e a v i e r p l a n e t s b y t h e s o l a r w i n d

E a r t h , M a r s , a n d Ve n u s w e r e a b l e t o h o l d o n t o s o m e o f t h e h e a v i e r g a s e s i n c l u d i n g w a t e r v a p o r a n d c a r b o n d i o x i d e

Nebular Hypothesis

Because o f the i r la rge s ize , the ou te r p lane ts g rav i t y was s t rong enough to

re ta in a l l o f these gases .

Layers form on the Earth Short ly af ter Ear th formed, the

decay of radioact ive e lements, combined wi th heat re leased by col l id ing par t ic les, producing some mel t ing of i t ’s in ter ior

This allowed the denser elements, mostly iron and nickel, to sink to Earth’s center because of gravity. The less dense rocky components floated outward toward the surface.

Th is s ink ing and f loa t ing i s be l ieved to be s t i l l be go ing on , bu t on a much smal le r sca le .

As a resu l t , t he Ear th ’s in te r io r i s no t made up o f un i fo rm mater ia l . I t cons is ts ins tead o f layers o f

d i f f e r ing mater ia ls .