COURSE: ES2202

ASSIGNMENT: 0

GROUP MEMBERS: SUSHOVAN MONDAL (13MS050),

TANTU DAS (13MS052), SUMAN DAS (13MS019)

ANSWERS

Q.2.

Observed features from the given map:

1. Maximum part of the map is blue coloured: Blue colour indicates the

part of water on the earth. As ¾ part of Earth if full of water so

maximum part of map is looked bluish.

2. Southern part of the map is more bluish than North: That indicates that

the part of land is more in the north hemisphere than south.

3. In the land part, various parts are indicated by various colour: The

colour is actually indicating elevation in various places. Like red colour is

for elevation greater than 6000 m and green is for sea level and yellow is

for greater than sea level but lesser than mountain range.

4. The total map is divided in many parts by various boundary lines: The

surface of the earth, i.e Lithosphere is constructed by various moving

plates like structure. And the plates are separated by boundary line

called plate boundary.

5. The boundaries are not continuous everywhere: The boundaries are

not continuous everywhere. The discontinuity is due to actually

transform fault that is actually formed by parallel movement of plates.

6. The contrast of the colour blue is not same all over the ocean part:

Maximum part of the oceanic part is deep blue. But some of the places

are light blue and some part is violet. The contrast difference is due to

the depth of the ocean.

7. Light blue colour at the both side of boundary in ocean: In the ocean

maximum part of the boundaries are divergent boundaries. And at that

place new lithospheric materials come from the mantle and those

accumulate there and the depth is lesser tan other part of the ocean.

8. The shape of the continents indicates that at a time the continents are

joined to each other and by the plate movement they are now separated

from each other.

9. Many mountain ranges are situated at the junction of continetnt-

continent convergent boundaries: At the continental convergent

boundary the places are indicated by the red colour. That indicates that

at the continental convergent boundary one plate is riding on the others.

Q.3.

Name Area(Steradian) Velocity(cm/year) Length of subduction zone(km)

Length of spreading ridge(km)

INDIAN 0.307 6 8212 3200 PACIFIC 2.567 8.1 21000 18300 N.AMERICA 1.365 1.15 3845 10000 S.AMERICA 1.031 1.45 10045 12100 EURASIAN 1.196 0.95 13455 13525 NAZCA 0.397 7.55 6400 6300

By the over lapping of the given map on Google Earth we got the total length

of subduction zone and spreading ridge of the six plate that is given above. And

plotted as, 1. Area of the plate vs velocity, 2. Length of subduction zone vs

velocity of plate and 3. Length of the spreading ridge vs velocity of plate.And

the plots are like ,

OBSERVATION: Plots are looking alike. From the obtained data and the plots

we observed that Small areal plates (like INDIAN ,NAZCA) with high velocity are

quite rapidly converging than making new mid oceanic ridges and another

thing is that quite huge plate like NORTH and SOUTH AMERICAN plate, velocity

is low but their subduction zone is lesser than mid oceanic spreading ridge. So

the interrelation between various plate boundary length and velocity the total

area remain constant.

Q.4.

OBSERVATION:

This is the plot of earth quake affected area’s longitude vs latitude. This shows

us the actual belts and outlines of affected areas by earth quake. By this plot

we can say that the maximum earth quake affected areas are mainly situated

at the plate boundaries. From the plot we can see that at the middle of the

boundary lines there are not so much affected areas. And there is a belt like of

structure at the border of pacific plate and Eurasian plate also.

OBSERVATIONS:

This is the plot of the magnitude of the earth quake vs depth at various

locations on earth. We can see from the plot that at the lower depth that is

near the surface there are many possibility of the intensity of earth quake.

There may be high intensity or low. But if we go to more depth, then the

probability of high intensity is low. So we can say that if we go distant from the

centre to surface then the intensity become lower.

We can also see that About 300 to 400 km depth there is a discontinuity. So

there may be liquid material or maybe some state from there the wave can not

pass.