Karnataka 1st PUC Geography Question Bank Chapter 6 Hydrosphere Questions and Answers Solution, Notes by Expert Teacher Priya Verma. Karnataka Class 11 Geography Solution Chapter 6.
There are 2 Parts in Karnataka Class 11 Textbook. Here You will find Part A Fundamentals of Physical Geography’s Chapter 6 Hydrosphere (Topography of the Ocean Floor, Temperature and Salinity, Movements of the Ocean water, Tides, Conservation of Oceans).
Karnataka 1st PUC Geography Question Bank Chapter 6 – Hydrosphere Solution
- State – Karnataka.
- Class – 1st PUC / Class 11
- Subject – Geography.
- Topic – Solution / Notes.
- Chapter – 6
- Chapter Name – Hydrosphere.
- Subpart – Topography of the Ocean Floor, Temperature and Salinity, Movements of the Ocean water, Tides, Conservation of Oceans.
(I) Answer the following in a word or a sentence each.
(1) What is Hydrological cycle?
Answer :
Hydrological cycle is the process of formation of water in the earth.
(2) Define Oceanography.
Answer :
Oceanography is the scientific study of waterbodies.
(3) Which instrument is used to measure depth of the Ocean?
Answer :
Depth of the ocean is measured by fathometer.
(4) Name the region which covers largest area in the ocean floor.
Answer :
The region which covers the largest area of the ocean floor is known as deep sea plains.
(5) What is Salinity?
Answer :
Salinity is the total amount of dissolved salts present in the water body.
(6) Which lines are drawn on the map to show places having same salinity?
Answer :
Isohalines show the places of the same salinity on the map.
(7) What are Sea waves?
Answer :
Sea waves are the undulations formed on the sea surface by the upward and downward movement of the sea water.
(8) Where do we find the ‘Agulhas current?
Answer :
Agulhas current is found in east of South Africa.
(9) How does a tide occur?
Answer :
Tides are caused by the gravitational attraction of the moon, sun, and the centrifugal force of the earth.
(10) What is Tidal period?
Answer :
Tidal period is the time-period between successive high tide and low tides.
(II) Answer the following in two or three sentences each.
(1) Name the four submarine relief features of the Ocean floor.
Answer :
The major submarine relief features of the ocean floor are the continental shelf, the continental slope, the deep-sea plains, and the ocean deep.
(2) Mention the important features of Continental Shelf.
Answer :
Continental shelf is the shallow submerged extension of the continent. It is the shallowest part of the ocean floor with its depth varying between 20 to 600m. It is mostly covered with silt, sand, mud, and sediments. It is the region for the construction of ports, harbours, major fishing grounds etc.
(3) Why is Ocean deep or Trench important in the Ocean bottom?
Answer :
Ocean deep also known as ocean trench is the important part of the ocean relief because it is the zone of subduction of oceanic crust and the continental crust. It is the area where most of the earthquakes and tsunamis are generated.
(4) State any four factors that influence on the distribution of temperature in the ocean.
Answer :
Factors which effect the distribution of temperature in the ocean water are latitudes, prevailing winds, ocean currents, unequal distribution of land and water etc.
(5) Mention any four dissolved minerals in the Ocean water.
Answer :
Dissolved minerals found in the ocean water are magnesium sulphate, magnesium chloride, sodium chloride, calcium carbonate, potassium sulphate etc.
(6) What factors affect the salinity in the Ocean water?
Answer :
There are various factors which affect the salinity of the ocean water like- evaporation, precipitation, freshwater mixing with the ocean water, trade winds etc.
(7) Name the two types of Ocean currents. Where are they found?
Answer :
Some famous ocean currents are Mozambique current found between Africa and Madagascar in Mozambique channel; Agulhas current found in east coast of South Africa etc.
(8) Mention any four South Indian Ocean currents.
Answer :
Four South Indian Ocean currents are Madagascar current, Agulhas current, West Australian cold current and West wind drift.
(9) Distinguish between High tide and Low tide.
Answer :
When sea level rises it is known as high tide and when it falls it is known as low tide. High tide is also known as Flood tide and low tide is also known as ebb tide.
(10) Mention any four uses of tides.
Answer :
Some important uses of tides are-
- Help in harbouring of ships and navigation
- Clean the entrance of the ports, harbours, and river mouths.
- Fishing and aquaculture activities.
- Promote salt and foam production in the coastal areas.
(III) Answer the following.
(1) Explain the topography of the Ocean floor with a diagram.
Answer :
The ocean floor is characterized by various relief features. They are also known as topographical features or submarine features. They are-
- Continentalshelf– It is the shallowest part of the ocean and it is the submerged extension of the continent. It varies from 20 to 600 m. It is usually covered with thick deposits of silt, sand, mud etc. It has many ports and harbours, major fishing grounds, and is famous for natural resources like oil and natural gas etc.
- Thecontinentalslope– It is the boundary between the continental crust and the oceanic crust. Its depth varies from 200m to 2000m. Submarine canyons are the unique feature of this part of ocean floor.
- The deep-sea plains– It is the largest part of the ocean floor. It lies between 3000 to 6000 m in the ocean floor. Sea mounts, ridges and guyots are the unique features of this region.
● The ocean deep or trench– It is an arc shaped depression in the ocean floor, and it is the deepest part of the ocean. It is the subduction zone between the oceanic crust and the continental crust.
(2) Describe the salient features of Salinity of the Ocean water.
Answer :
Salinity of the ocean is the total amount of the dissolved salts in the ocean water. Ocean water contains various minerals like sodium chlorine, magnesium chloride, magnesium sulphate, calcium sulphate, calcium carbonate etc. There are various factors which affect the salinity of the ocean-
- Evaporation
- Precipitation
- Mixing of freshwater with the ocean water
- Trade winds take saline water from the areas of high salinity to the areas of low salinity.
Salinity is also not uniform in all the water bodies present on the earth. The average salinity of the ocean water is 35 parts per thousand. Whereas the horizontal and vertical distribution of the salinity depends on the latitude, precipitation, mixing of fresh water etc. Isohalines are the lines drawn on the map which joins the places of same salinity.
(3) Explain the Indian Ocean currents with the help of Maps.
Answer :
Indian ocean is surrounded by the continents of Africa, Asia and Australia and it is the third largest ocean in the world. It is majorly located in the Southern Hemisphere. Indian ocean currents are largely influenced by the shaped of the landmass and monsoon winds. They are divided into two types-
- North Indian Ocean currents- In the northern Indian ocean direction of the ocean currents are reversed because of monsoonal change. The southwest monsoon and the northeast monsoon change the direction twice a year. The Arabian Sea warm current also known as Somalia current flows in the clockwise direction along the east coast of Somalia.
- South Indian Ocean currents- The southern Indian Ocean currents are independent of the monsoonal winds. They flow from Indonesian archipelago towards the eastern coast of Africa. After reaching Madagascar it divides into two branches- Mozambique current and the Madagascar current. These two branches meet in the east of South Africa and form Agulhas current.
(4) Briefly explain the types of tides.
Answer :
The rise and fall in the water level of ocean and sea is called as tide. They are caused by the gravitational attraction of moon, gravitational attraction of sun and the centrifugal force of sun. The rise in sea level is known as high tide or the flood tide and the fall in sea level is known as low tide or ebb tide. Tides are broadly classified into two types-
Springtides– They occur on the full moon or the new moon day. When the sun, moon and earth lie on same line then by the gravitational attraction of the sun and the moon the length of the high tides increase. They are known as spring tides.
Neaptides– They occur when the sun and the earth are in same line and the moon is in perpendicular direction, then the gravitational field of the sun and the moon act on opposite direction and the tides are formed of minimum length. They are also known as neap tides and are formed when moon is in its first quarter or the third or the last quarter.
(5) What is Conservation of Ocean? Mention the important measures.
Answer :
Oceans are the rich source of various economic and natural functions. They are rich in various resources, but its over exploitation is a major challenge in the 21st century. Overexploitation in the form of extraction of minerals like crude oil, natural gas, thorium, magnetite, common salt, power generation, marine food resources etc.Its over exploitation is becoming a challenge to the marine organisms and a major cause of pollution. Some important measures which can help in ocean conservation are-
- Proper sewage disposal and handling
- Controlling oil spills
- Use of hazardous substances and pesticides must be reduced.
- Stopping the dumping of nuclear waste
- Controlled and sustainable fishing activities
- Regulated mining activities
- Awareness generation for marine life protection.
Also See: 1st PUC Geography Question Bank Chapter No. 4 Question Answer