Jot down the first thing that comes to your mind.

I’ve been thinking about the ocean and its mystery underwater.

In simple terms, an ocean is a vast body of saltwater that covers most of the Earth’s surface. It’s where you find beaches, marine life like fish and whales, and it affects the weather and climate.

There is only one ocean, It is divided into three named parts by international agreement: the Atlantic, Pacific, and Indian ocean (International Hydrographic Bureau, 1953), Seas, which are part of the ocean, are defined in several ways. However, from newest update there are 5 names of ocean now. Here’s the list of the five oceans on Earth ordered from largest to smallest:

Pacific Ocean
Atlantic Ocean
Indian Ocean
Southern Ocean
Arctic Ocean

There’s also a term of The Seven Seas include the Arctic, North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, and Southern oceans.

These oceans cover the majority of the Earth’s surface and are interconnected, playing vital roles in regulating climate, supporting marine life, and shaping the planet’s geography.

Oceans are essential to life on Earth, regulating climate, providing habitat for countless marine species, and supporting various ecosystems. They influence weather patterns, absorb carbon dioxide, and play a crucial role in the global water cycle. Additionally, oceans are important for human activities such as transportation, fishing, tourism, and resource extraction.

Our knowledge of oceanic currents, winds, waves, and tides goes back thousands of years. Polynesian navigators traded over long distances in the Pacific as early as 4000 BC (Service, 1996). Pytheas explored the Atlantic from Italy to Norway in 325 Bc. Arabic traders used their knowledge of the reversing winds and currents in the Indian Ocean to establish trade routes to China in the Middle Ages and later to Zanzibar on the African coast. And, the connection between tides and the sun and moon was described in the Samaveda of the Indian Vedic period extending from 2000 to 1400 Bc (Pugh, 1987). Those oceanographers who tend to accept as true only that which has been measured by instruments, have much to learn from those who earned their living on the ocean.

Slow ships of the 19th and 20th centuries gave way to satellites toward the end of the 20th century. Satellites now observe the oceans, air, and land, Their data, when fed into numerical models allowes the study of earth as a system.

Difference Between Ocean and Sea

The main difference between an ocean and a sea lies in their size, depth, and location.

Oceans are the largest bodies of saltwater on Earth, covering about 71% of the planet’s surface. They are immense, deep, and interconnected, with distinct regions such as the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean.

Seas are smaller bodies of saltwater that are partially enclosed by land. They are typically part of an ocean or connected to it, and they can vary in size, depth, and salinity. Examples include the Mediterranean Sea, the Caribbean Sea, and the North Sea.

In summary, oceans are vast expanses of saltwater that cover most of the Earth’s surface, while seas are smaller, partially enclosed bodies of saltwater usually connected to oceans.

Mystery

The underwater world holds many geological mysteries waiting to be explored and understood.

Submarine Canyons

These are deep, steep-sided valleys cut into the continental slope and continental shelf. The exact processes that form submarine canyons, such as erosion by turbidity currents or underwater landslides, are still not fully understood.

Submarine canyons play critical roles in marine ecology, nutrient cycling, and geological processes. They are dynamic and complex features that contribute to the health and functioning of marine ecosystems worldwide.

Deep-Sea Trenches

These are long, narrow depressions in the ocean floor, often associated with convergent plate boundaries where one tectonic plate is forced beneath another. The mechanisms that cause these trenches to form and their role in plate tectonics are areas of ongoing research. The deepest oceanic trench on Earth is Mariana trench, located in the western Pacific Ocean, about 200 kilometers east of the Mariana Islands.

Deep-sea trenches serve several important functions in the Earth’s geology and oceanography:

Subduction zones

Deep-sea trenches are often associated with subduction zones, where one tectonic plate is forced beneath another into the Earth’s mantle. This process, known as subduction, plays a crucial role in the recycling of Earth’s crust and the formation of volcanic arcs and mountain ranges. Deep-sea trenches provide the necessary topographic relief for the downward movement of oceanic plates into the mantle.

Earthquake generation

Deep-sea trenches are sites of intense tectonic activity and are prone to large earthquakes and associated tsunamis. The movement of tectonic plates along subduction zones can generate significant seismic energy, leading to earthquakes that can cause widespread destruction and impact coastal regions.

Tsunamis are low-frequency ocean waves generated by submarine earthquakes. The sudden motion of sea floor over distances of a hundred or more kilometers generates waves with periods of around 12 minutes. The waves are not noticeable at sea, but after slowing on approach to the coast, and after refraction by subsea features, they can come ashore and surge to heights ten or more meters above sea level. In an extreme example, the great 2004 Indian Ocean tsunami destroyed hundreds of villages, killing at least 200,000 people.

What are some signs of tsunami?

When it comes to signs of an impending tsunami, it’s crucial to pay attention to natural indicators. Here are some details:

Earthquakes, tsunamis are often triggered by underwater earthquakes. A significant earthquake, especially one with a magnitude of 7 or higher on the Richter scale, near a coastline can be a warning sign.
Unusual Ocean Behavior, keep an eye out for any abnormal changes in the ocean, such as rapid changes in sea level where water recedes significantly from the shore or advances inland unusually quickly. You might also hear a roaring or rumbling sound coming from the ocean.
Visual Clues, watch for visual cues such as the presence of frothy water resembling the white of a boiling pot, or the sudden formation of a large wave that seems out of place.
Emergency Alerts, listen for official tsunami warnings issued by local authorities through emergency alert systems, sirens, or broadcast media.
Natural Warnings, animals may exhibit unusual behavior, such as birds fleeing inland or marine life behaving erratically, which could be a sign of an impending tsunami.
Previous Experience, if you’re in an area prone to tsunamis, pay attention to historical data and local knowledge. Familiarize yourself with evacuation routes and community disaster plans.

It’s essential to take any of these signs seriously and immediately move to higher ground if you suspect a tsunami is imminent. Being prepared and knowing how to respond can save lives.

What to do if there’s a tsunami?

If you find yourself in an area under threat of a tsunami, here’s what you should do:

Evacuate to Higher Ground, move immediately to higher ground or inland away from the coast. Tsunamis can travel inland for several miles, so it’s crucial to get to higher ground as quickly as possible.
Follow Evacuation Routes, use designated evacuation routes if they are available. These routes are typically marked and are designed to lead you to safety.
Listen to Authorities, pay attention to official warnings and follow the instructions provided by local authorities. They will have the most up-to-date information and guidance on what actions to take.
Stay Informed, keep tuned to local news and emergency alert systems for updates on the situation. Information may change rapidly during a tsunami event.
Do Not Return Until Given the All-Clear, do not return to the evacuated area until authorities have declared it safe to do so. Tsunami waves often come in multiple waves, and it’s important to wait for official confirmation that the threat has passed.
Take Shelter, if you cannot evacuate in time, seek shelter in a sturdy, multi-story building or climb to the upper floors if possible. Avoid being near windows or doors facing the coast.
Prepare an Emergency Kit, have an emergency kit ready with essentials such as water, non-perishable food, a flashlight, a first aid kit, and any necessary medications.

Tsunami can be incredibly dangerous and can cause widespread devastation. It’s essential to take immediate action and prioritize your safety if a tsunami warning is issued.

What to do if there’s an earthquake?

During an earthquake, it’s crucial to take quick and decisive actions to ensure your safety. Here’s what to do:

Drop, Cover, and Hold On, drop to the ground to prevent being knocked over. Take cover under a sturdy piece of furniture, such as a table or desk, and hold on until the shaking stops. If there’s no furniture nearby, cover your head and neck with your arms and seek shelter against an interior wall away from windows.
Stay Indoors, if you’re inside a building, stay indoors and do not try to run outside. Most injuries during earthquakes occur when people try to move to a different location within a building or attempt to exit while the shaking is still occurring.
Stay Away from Windows, move away from windows, glass doors, or any other objects that could shatter and cause injury.
Brace Yourself, if you’re unable to take cover under furniture, crouch against an interior wall and protect your head and neck with your arms.
If Outside, Move to an Open Area, if you’re outside when the earthquake hits, move to an open area away from buildings, trees, streetlights, and utility wires. Drop to the ground and cover your head and neck with your arms.
Be Prepared for Aftershocks, after the initial earthquake, there may be aftershocks smaller tremors that follow the main quake. Be prepared for these and take the same protective actions.
Follow Local Emergency Procedures, stay tuned to local news and follow any instructions or evacuation orders issued by local authorities.
Check for Hazards, after the shaking stops, be cautious of potential hazards such as gas leaks, downed power lines, or damaged buildings. If you smell gas or suspect a leak, turn off the main gas valve and evacuate the area immediately.

Earthquakes can happen without warning, so it’s essential to be prepared and know what to do to protect yourself and others during a seismic event.

Oceanic circulation

Deep-sea trenches can influence ocean circulation patterns by acting as barriers to the movement of deep-water currents. The topography of trenches can create obstacles that deflect or redirect ocean currents, affecting the distribution of heat, nutrients, and dissolved gases in the ocean.

Habitats for deep-sea life

Despite the extreme environmental conditions, deep-sea trenches support unique ecosystems of marine life adapted tohigh pressures, cold temperatures, and limited food resources. Organisms such as deep-sea fish, invertebrates, and microbial communities inhabit the depths of trenches, where they play important roles in nutrient cycling and energy transfer.

Deep-sea trenches are dynamic and complex features that play critical roles in the Earth’s geology, oceanography, and ecology. They are key sites for scientific research and provide valuable insights into the processes shaping our planet.

Seamounts and Underwater Volcanoes

These are underwater mountains formed by volcanic activity. Understanding the formation and distribution of seamounts can provide insights into the dynamics of mantle plumes and the evolution of oceanic crust.

Seamounts and underwater volcanoes are important features of the marine environment that contribute to biodiversity, biological productivity, and geological processes. They are hotpots of marine life and are essential for maintaining healthy and resilient ocean ecosystems.

Several underwater geological features are considered as mountains due to their significant elevation relative to the surrounding seafloor. Some of these underwater mountains include:

Seamounts

Are underwater mountains that rise from the seafloor but do not reach the ocean surface. They can vary in size and shape, with some rising thousands of meters from the ocean floor. Seamounts are often volcanic in origin, formed by the accumulation of lava and volcanic debris.

Guyots

Also known as tablemounts, are flat-topped seamounts that were once volcanic islands but have since subsided beneath the ocean surface. The flat summit of a guyot is typically the result of erosion by waves when the seamount was above sea level.

Mid-Ocean Ridges

Are long underwater mountain chains rather than individual mountains, they can still be considered as geological features with significant elevation. Mid-ocean ridges form along divergent plate boundaries and are characterized by volcanic activity and the creation of new oceanic crust.

Ridge Systems

In addition to mid-ocean ridge, there are other ridge systems in the oceans that may have mountainous features. These include spreading ridges associated with rift zones and fracture zones that result from tectonic activity.

These underwater mountains play important roles in oceanic ecosystems, providing habitats for diverse marine life and influencing ocean circulation patterns.

Several underwater geological features formed by volcanic activity are considered mountains due to their significant elevation and volcanic origins. Some of these include Seamounts and…

Submarine Volcanoes

Submarine volcanoes are volcanic vents on the ocean floor that erupt magma, gases, and volcanic ash. These eruptions can build up underwater mountains over time, similar to how terrestrial volcanoes build up mountains on land. Submarine volcanoes can vary in size and activity, ranging from small seamounts to large volcanic edifices.

Ridge Volcanoes

Some underwater mountains are associated with mid-ocean ridges or volcanic island arcs, where tectonic activity causes magma to rise to the surface and form volcanic features. These ridge volcanoes can contribute to the formation of underwater mountain chains and play a role in the creation of new oceanic crust.

These underwater geological features formed by volcanic activity are important for understanding Earth’s geology and provide unique habitats for marine life.

Hydrothermal Vents

These are underwater geysers that release hot, mineral-rich water into the ocean. Hydrothermal vents support unique ecosystems of organisms adapted to extreme conditions, but the processes that sustain these ecosystems and their potential contributions to the Earth’s chemistry are still being studied.

Hydrothermal refers to processes or phenomena involving hot water or fluids. In the context of geology and oceanography, hydrothermal typically refers to the circulation of hot water through the Earth’s crust, often associated with volcanic activity and the movement of tectonic plates.

One common example of hydrothermal activity is hydrothermal vents, which are openings in the seafloor where hot, mineral-rich water emerges from beneath the Earth’s crust into the ocean. These vents are typically found along mid-ocean ridges, where tectonic plates are spreading apart, and they are associated with underwater volcanic activity.

Marine Geology of Polar Regions

The geology beneath the ice-covered polar oceans, such as the Arctic Ocean and parts of the Southern Ocean, remains relatively poorly understood due to the logistical challenges of studying these remote and harsh environments. Unlocking the secrets of these regions could provide valuable insights into past climate change and the geological history of the Earth.

Underwater Sea In The Ocean

There are underwater bodies of water within the ocean, known as brine pools or brine lakes. These are areas of highly concentrated saltwater that are denser than the surrounding seawater and can form depressions on the ocean floor. Brine pools and lakes can be found in various locations around the world, particularly in deep-sea basins and areas where there is a high influx of saltwater.

Brine pools are often associated with underwater seeps or vents where hydrocarbons or other fluids are released from the seafloor. These fluids mix with seawater and can become supersaturated with salt, leading to the formation of brine pools. The high salinity of these pools creates a distinct layer of water that can be separated from the surrounding seawater by a density barrier.

Brine pools and lakes are unique ecosystems that support specialized forms of life adapted to extreme conditions, including high salinity, high pressure, and low oxygen levels. These ecosystems can include microbial communities, chemosynthetic bacteria, and specialized invertebrates that are able to tolerate the harsh conditions of the brine environment.

Sound in the Ocean

Sound provides the only convenient means for transmitting information over great distances in the ocean, and it is the only signal that can be used for the remotely sensing of the ocean below a depth of a few tens of meters. Sound is used to measure the properties of the sea floor, the depth of the ocean, temperature, and currents. Whales and other ocean animals use sound to navigate, communicate over great distances, and to find food.

State of the Sea

The sun and the atmosphere drive directly or indirectly almost all dynamical processes in the ocean. The dominant external sources and sinks of energy are sunlight, evaporation, infrared emissions from the sea surface, and sensible heating of the sea by warm or cold winds. Winds drive the ocean’s surface circulation down to depths of around a kilometer. Deep mixing drives to some extent the deeper currents in the ocean.

Wind at sea has been measured for centuries. Beaufort Scale By far the most common source of wind data have been reports of speed based on the Beaufort scale. Even in 1990, 60% of winds reported from the North Atlantic used the Beaufort scale. The scale is based on features, such as foam coverage and wave shape, seen by an observer on a ship.

Beaufort Wind Scale and State of the Sea

Beaufort Number	Descriptive Term	m/s	Appearance of the Sea
0	Calm	0	Sea like a mirror.
1	Light Air	1.2	Ripples with appearance of scales; no foam crests.
2	Light Breeze	2.8	Small wavelets; crests of glassy appearance, not breaking.
3	Gentle Breeze	4.9	Large wavelets; crests begin to break; scattered whitecaps.
4	Moderate Breeze	7.7	Small waves, becoming longer; numerous whitecaps.
5	Fresh Breeze	10.5	Moderate waves, taking longer to form; many whitecaps; some spray.
6	Strong Breeze	13.1	Large waves forming; whitecaps everywhere; more spray.
7	Near Gale	15.8	Sea heaps up; white foam from breaking waves begins to be blown into streaks
8	Gale	18.8	Moderately high waves of greater length; edges of crests begin to break into spindrift; foam is blown in well-marked streaks.
9	Strong Gale	22.1	High waves; sea begins to roll; dense streaks of foam; spray may reduce visibility.
10	Storm	25.9	Very high waves with overhanging crests; sea takes white appearance as foam is blown in very dense streaks; rolling is heavy and visibility reduced.
11	Violent Storm	30.2	Exceptionally high waves; sea covered with white foam patches; visibility still more reduced.
12	Hurricane	35.2	Air is filled with foam; sea completely white with driving spray; visibility greatly reduced.

Table of Beaufort Scale and State of the Sea

From Kent and Taylor (1997)

Ships are unevenly distributed over the ocean. Ships tend to avoid high latitudes in winter and hurricanes in summer, and few ships cross the southern hemisphere
Observers may fail to take care in observing oceanic conditions on which the Beaufort scale is based.
The coding of the data may have errors, which can result in the reports having the wrong location.
Overall, the accuracy is probably no better than around 10%.

Scatterometers Observations of winds at sea are coming more and more from instruments on satellites, and scatterometers are the most common source of the observations. The scatterometer is a instrument very much like a radar that measures the scatter of centimeter-wavelength radio waves from small, centimeter-wavelength waves on the sea surface. The area of the sea covered by small waves, and their amplitude depends on wind speed and direction. The scatterometer measures scatter from 2-4 directions, from which wind speed and direction are calculated.

Special-Sensor Microwave/Imager (SsM/1) is another satellite instrument that is widely used for measuring wind speed, carried since 1987 on the satellites of the U.S. Defense Meteorological Satellite Program in orbits similar to the NOAA polar-orbiting meteorological satellites. The instrument measures the microwave radiation emitted from the sea at an angle near 60° from the vertical. The emission is a function of wind speed, water vapor in the atmosphere, and the amount of water in cloud drops. By observing several frequencies simultaneously, data from the instrument are used for calculating the surface wind speed.

Anemometer is a device used to measure wind speed. There are different types of anemometers, including cup anemometers, propeller anemometers, and sonic anemometers. Cup and propeller anemometers consist of rotating cups or blades that spin in the wind, with the speed of rotation proportional to the wind speed. Sonic anemometers use ultrasonic signals to measure wind speed and direction.

Wind vane or weather vane, is a device used to measure wind direction. It consists of a flat or arrow-shaped plate mounted on a pivot, with one end pointed into the wind. As the wind changes direction, the vane rotates to align with the wind, indicating the direction from which the wind is blowing.

Windsock is a conical textile tube that is open at both ends, with one end attached to a pole or mast. Windsocks are often used at airports and airstrips to indicate wind direction and strength. The direction in which the windsock points indicates the direction from which the wind is blowing, and the angle of the windsock relative to the pole can provide an estimate of wind speed.

Pitot tube is a device used to measure airspeed on aircraft and is also used in some applications to measure wind speed. It consists of a small tube with an opening facing into the wind and another opening perpendicular to the airflow. The difference in pressure between the two openings is used to calculate wind speed.

The Southern Oscilliation

El Niño

El Niño is a climate phenomenon characterized by the periodic warming of sea surface temperatures in the central and eastern equatorial Pacific Ocean. This warming disrupts normal oceanic and atmospheric circulation patterns and can have significant impacts on weather patterns around the world.

During an El Niño event, warm ocean waters in the central and eastern Pacific Ocean extend farther eastward than usual, leading to changes in atmospheric circulation.

El Niño events typically occur every two to seven years and can last for several months to over a year. They are part of a larger climate cycle known as the El Niño-Southern Oscillation (ENSO), which also includes La Niña events (characterized by cooler-than-average sea surface temperatures) and neutral conditions.

La Niña

La Niña is the counterpart to El Niño and is part of the larger climate phenomenon known as the El Niño-Southern Oscillation (ENSO). La Niña is characterized by cooler-than-average sea surface temperatures in the central and eastern equatorial Pacific Ocean.

During a La Niña event, the normal oceanic and atmospheric circulation patterns that exist in the tropical Pacific Ocean are strengthened and intensified.

La Niña events typically occur every two to seven years and can last for several months to over a year.

Both El Niño and La Niña have widespread impacts on agriculture, fisheries, water resources, and economies around the world.

The Southern Oscillation refers to the natural back-and-forth movement of air pressure patterns over the tropical Pacific Ocean. During normal times, the pressure is higher in the eastern Pacific and lower in the western Pacific, creating steady trade winds. However, during El Niño and La Niña events, this pattern changes, affecting global weather patterns.

The Southern Oscillation is an important component of the Earth’s climate system and plays a key role in the development and evolution of El Niño and La Niña events.

There are several actions humans can take to preserve the oceans, seas, and water on Earth:

1. Reduce Plastic Pollution

Minimize the use of single-use plastics and properly dispose of plastic waste to prevent it from entering water bodies.

2. Sustainable Fishing Practices

Support sustainable fishing practices to prevent overfishing and protect marine biodiversity.

3. Reduce Carbon Footprint

Decrease carbon emissions by using renewable energy sources, reducing reliance on fossil fuels, and adopting energy-efficient practices to mitigate the impacts of climate change on marine ecosystems.

4. Conserve Water

Practice water conservation techniques such as fixing leaks, using water-efficient appliances, and reducing water consumption to preserve freshwater sources and reduce pressure on aquatic ecosystems.

5. Protect Coastal Areas

Preserve coastal habitats such as mangroves, coral reefs, and wetlands, which provide essential ecosystem services and serve as natural buffers against storms and erosion.

6. Support Marine Conservation Efforts

Advocate for the establishment of marine protected areas, support conservation organizations, and participate in beach clean-up initiatives to protect marine habitats and species.

7. Educate and Raise Awareness

Increase public awareness about the importance of ocean conservation and promote sustainable behaviors through education, outreach, and community engagement efforts.

If you wanna read more about oceanography, I always add my reference.

Reference

Stewart, R. H. (2006). Introduction To Physical Oceanography. Texas: Department of Oceanography Texas A & M University.

If you love solving puzzle and sudoku or interested to discuss about anything you can visit my social:

Social Links

CLICK HERE TO SUPPORT US

Ocean

Difference Between Ocean and Sea

Mystery

Submarine Canyons