This ppt will help to understand the concept of water mass in the world ocean. It gives an overview of it's origin, formation, distribution etc. in the world. It is also helpfull for Fisheries Science students.
Oceans also contain a huge amount of mineral resources. Deep ocean basins are the zones of continuous sedimentation. The oceans are the final destination for many of all the sediments to be deposited. About 200 million years of earth history are available in the fossiliferous sediments deposited within the ocean basins. This module explains the characteristics of marine sediments.
Oceans also contain a huge amount of mineral resources. Deep ocean basins are the zones of continuous sedimentation. The oceans are the final destination for many of all the sediments to be deposited. About 200 million years of earth history are available in the fossiliferous sediments deposited within the ocean basins. This module explains the characteristics of marine sediments.
1. DEFINITIONS OF OCEANOGRAPHY:-
2. Branches of oceanography
3. Nature of Oceanography
4. A Geographical approach into Oceanography
5. Importance of Oceanography
6. Contribution of oceanographers
7. DEVELOPMENT OF MODERN OCEANOGRAPHY
Seas and oceans are very huge bodies of saline waters. Their distribution and dynamics are very influential in several ways. Understanding the properties of seawater is inevitable in oceanographic studies. Seawater is one of the most fascinating and plentiful substances on the planet. The basic properties of seawater and their distribution, the interchange of properties between sea and atmosphere or land, the transmission of energy within the sea, and the geochemical laws which are governing the composition of seawater and marine sediments, are the fundamental aspects studied in the subject oceanography.
seawater is life to many organisms and plants.
it consists of various nutrients which help in the growth and developments of flora and fauna present in the seawater
A presentation to study the origin and development of oceanographic science in details from the ancient peoples to the modern period. This presentation will be very much helpful for the learners of this discipline.
The study of physical oceanography helps in understanding all these aspects in detail. Let us see most of these factors and processes in our future modules. Mathematical models of all these processes are also developed using these phenomena and mechanisms. The individual aspects of all the elements of physical oceanography are to be studied in detail.
1. DEFINITIONS OF OCEANOGRAPHY:-
2. Branches of oceanography
3. Nature of Oceanography
4. A Geographical approach into Oceanography
5. Importance of Oceanography
6. Contribution of oceanographers
7. DEVELOPMENT OF MODERN OCEANOGRAPHY
Seas and oceans are very huge bodies of saline waters. Their distribution and dynamics are very influential in several ways. Understanding the properties of seawater is inevitable in oceanographic studies. Seawater is one of the most fascinating and plentiful substances on the planet. The basic properties of seawater and their distribution, the interchange of properties between sea and atmosphere or land, the transmission of energy within the sea, and the geochemical laws which are governing the composition of seawater and marine sediments, are the fundamental aspects studied in the subject oceanography.
seawater is life to many organisms and plants.
it consists of various nutrients which help in the growth and developments of flora and fauna present in the seawater
A presentation to study the origin and development of oceanographic science in details from the ancient peoples to the modern period. This presentation will be very much helpful for the learners of this discipline.
The study of physical oceanography helps in understanding all these aspects in detail. Let us see most of these factors and processes in our future modules. Mathematical models of all these processes are also developed using these phenomena and mechanisms. The individual aspects of all the elements of physical oceanography are to be studied in detail.
Explore the dynamic world of ocean water and currents with this engaging PPT lesson by IAS Next. Dive deep into the intricate mechanisms governing ocean currents, their impact on climate, marine life, and more. Gain insights into the significance of understanding oceanic processes for various competitive exams, including IAS. This comprehensive presentation combines visuals and informative content to make learning about oceanography both educational and enjoyable.
Thermohaline Circulation & Climate ChangeArulalan T
Today I have presented "The Thermohaline Circulation and Climate Change" as Mini-Project for our Science of Climate Change Course ! We can expect THC shutdown around 2050s... OMG ! Yes, we can expect "The Day After Tomorrow" around 2100... All the images credited to the reference papers except one T-S-Sigmat created by me using CDAT5.2.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. Definition
An oceanographic water mass is an identifiable body, in terms of density,
of water with a common formation history which has physical properties
distinct from surrounding water.
Water mass are stable, large water bodies and for their formation, water has
to sink down/ strong downwelling.
It is defined on the basis of uniform density, not in terms of temperature or
salinity.
A water type has a single value of salinity and a single value of
temperature associated with it, while a water mass takes into account a
range of temperatures and salinities. For eg..
cont...
3. Cont.....
Red Sea water (lying between Africa and Asia) is a water type
characterized by a temperature of 9°C and a salinity of 35.5 ‰. On the
other hand, North Atlantic Central Water (a water mass) is characterized
by a range of temperatures (4°C to 17°C) and salinity (35.1 ‰ to 36.2
‰).
A water mass may be considered to be made up of a combination of two
or more water types.
4. Formation
majority of water masses are formed in the polar latitudes, and are not formed
in tropical waters and temperate waters.
Cold, highly dense surface water sinks, spreads out horizontally, until it reaches
a level having the same constant density. The manner in which it spreads out
depends on its density in relation to the density of the surrounding water.
Downwelling is more required for water mass formation and more pronounced
under: a) brine extraction process, b) in absences of Pycnocline (not well
developed in Polar region)
5. Common water masses in the world ocean
Antarctic bottom water ( AABW), North Atlantic Deep
Water(NADW), Circumpolar Deep Water(CDW), Antarctic Intermediate
Water(AAIW),
Subantarctic Mode Water (SAMW), Arctic Intermediate Water (AIW),
North Pacific Intermediate Water (NPIW), the central waters of
various oceanic basins, and various ocean surface waters.
Different regions with different temperatures form water masses. Some
water masses are more dense than others depending on salinity. Freshwater
will float because it is less dense than salt water.
6. There are 6
water masses
sources
region in
world ocean:
North Pacific ( near Aleutian Island)
South Pacific(ANTARTICA)
Norweigian Sea
East Greenland(Arctic region)
Weddell Sea( Antartica)
Lazarev Sea( Part of Antartic Basin)
8. Distribution
In low and middle latitudes the vertical arrangement of water is such that we can
distinguish a surface layer, upper water (central and equatorial), intermediate water,
deep water, and in some localities, bottom water.
SURFACE LAYER: properties vary widely from one area to another, depending
on current variations, evaporation, precipitation, and various seasonal changes,
especially in the middle latitudes, so, not classified as a water mass or water
type. The surface layer is separated from deeper water by a transition layer
(the main thermocline)
CENTRAL WATER MASSES: found in relatively low latitudes although its source
region is in the region of the subtropical convergence. Central water is not usually
discernible at the surface and is generally relatively shallow. Its greatest thickness
is observed along its western boundaries.
Cont.....
9. EQUATORIAL WATER
MASSES: found in the Pacific and in
the Indian Ocean. In the Pacific it is
thought to originate on the southern
side of the equator.
Equatorial water is found in the
northern part of the Indian Ocean is
having higher salinities, probably
due to its mixing with the waters of
the Red Sea.
Cont....
Fig: Global distribution of upper waters (0-500 m). (source- Emery
et al.,2001)
10. INTERMEDIATE WATER
Intermediate water is found below
central water in all oceans.
Intermediate water includes Antarctic
intermediate water, Arctic intermediate
water, Mediterranean water, and Red
Sea water.
One of the characteristics of Antarctic
intermediate water is its low salinity
(34.1 ‰ to 34.6 ‰). In comparison to
the water around it, it displays the
lowest salinity values.Fig: Global distribution of intermediate water (1000-
3000m) ( source: Emery et al.,2001 )
11. DEEP AND BOTTOM WATER MASSES.
• In the deep ocean basins below
intermediate water, high density
deep and bottom water exists.
• These water masses form in both
hemispheres.
• In the Southern
Hemisphere, Antarctic bottom
water forms near the Antarctic
continent, while in the Northern
Hemisphere, Arctic deep and
bottom water forms in
northwestern Labrador Basin
• These water masses form at the
surface, sink, and spread out to fill
the deep-ocean basins.
FIg: Global distribution of deep and abyssal waters (3000....)bottom.
(Source: Emery et al.,2001)
12. TS-time diagrams
In oceanography, temperature-salinity
diagrams, sometimes called T-S diagrams, are
used to identify water masses.
The water mass can be identified by a relation of
the properties pertaining to temperature and
salinity.
Even though, density depends on the
temperature and salinity, it cannot be used for
identification, bcz two water mass may have
same density but temp. And salinity may
different.
In a T-S diagram, potential temperature (on the
vertical axis) is plotted versus salinity (on the
horizontal axis).
Fig: Water masses of the deep ocean as seen in a TS-
diagram and associated source water types.
(source: Tomczak et al., 2000)
14. THE THREE-LAYERED OCEAN
Using bathythermograph information
(temperature versus depth profiles), the
oceans display a basic three-layered
structure: the mixed layer, main
thermocline, and deep water layer.
The mixed layer is the upper
layer, constant warm temperatures which,
in middle latitudes, extends from the
surface to a maximum depth of about 450
meters, or 1,500 feet. Mixing processes
are done
by mechanical and convective process.
Fig: layers in ocean (source: internet)
15. The main thermocline is the central layer of the
ocean. It is found at the base of the mixed layer
and is marked by a rapid decrease of water
temperature with depth.
The seasonal thermocline comes about from the
gradual warming of the surface waters. The
warming takes place in the upper few hundred
feet of the surface, and results in the seasonal
thermocline becoming super-imposed on the main
thermocline.
The mid-latitude summer thermocline is more
pronounced than the thermocline of spring or
autumn.
Fig: Seasonal thermocline. (Source:
internet)
16. Deep Water Layer: The deep water
layer is the bottom layer of water,
which in the middle latitudes exists
below 1,200 meters.
This layer is characterized by fairly
constant cold temperatures, generally
less than 4°C.
Below 3,300 feet to a depth of
about 13,100 feet, water temperature
remains constant. At depths below
13,100 feet, the temperature ranges
from near freezing to just above the
freezing point of water as depth
increases.
Fig: reprentation of layers with depth ( source: NOAA)
18. It is a system of ocean currents that transport water around the world. While wind
primarily propels surface currents, deep currents are driven by differences in water
densities in a process called thermohaline circulation.
1)At the poles, cold ocean water becomes saltier and denser from evaporation and
ice formation. The cold, salty, dense water sinks and slowly spreads.
2) Because there are no continents to block the water, the current can flow freely
around Antarctica. Some water moves into the Indian Ocean while another current
travels to the Pacific Ocean.
3) Deep water surfaces in a process called upwelling.
4)The warm surface current flows north toward Greenland, completing the cycle.
19. Thank you
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