All About Water

Natural Disasters

Natural disasters are a natural hazards that causes human loss. Just a few natural disasters include hydrological disasters, earthquakes, and volcanic eruptions.

What Is a Natural Disaster?

A natural disaster is a natural hazard, but a natural hazard is not necessarily a natural disaster. A natural disaster becomes a natural hazard when it occurs near vulnerable human populations. Natural disasters kill people and cause financial damage. For example, an earthquake that strikes an uninhabited place is a natural hazard, but not a natural disaster because it doesn’t kill people or destroy human property. An earthquake that strikes San Francisco, however, is a natural disaster. The amount of damage that a natural disaster creates depends on people’s resilience, their ability to withstand and resist the disaster. Natural disasters come in a variety of forms.

Hydrological Disasters

Hydrological disasters are natural disasters caused by water. Hydrological disasters include floods, tropical cyclones, and tsunamis. Floods are often created by tropical cyclones, which produce storm surge. Tsunamis are caused by underwater earthquakes. Japan’s 2011 Tohoku earthquake and accompanying tsunami is estimated to have killed up to 25,000 people.

Earthquakes

An earthquake is a shaking of the Earth’s crust that happens when tectonic plates collide. These shakings differ in magnitude depending on the force of the tectonic plates’ collision. The underground place where the tectonic plates collide is called the “focus.” The point directly above the focus, which suffers the most damage, is called the “epicenter.” An earthquake alone won’t usually kill people or wildlife. However, earthquakes usually trigger secondary events that do cause damage. Earthquakes make buildings collapse and cause fires and tsunamis. These secondary events are what cause earthquakes to be perceived as natural disasters.  Societies can lessen their vulnerability to earthquakes by monitoring underground activity, warning people when earthquakes are going to occur, planning evacuations, and by building safer buildings and safety systems.

Volcanic Eruptions

Volcanic eruptions can destroy their surroundings in several ways. The initial volcanic explosion can produce dangerous rock falls. The lava produced by volcanic eruptions may trickle down, destroying nearby buildings and plants. Volcanic eruptions also produce toxic ash clouds, which can settle over nearby places. Even the smallest quantities of ash are toxic if inhaled, and enough ash can collapse roofs. The most destructive part of a volcanic eruption is pyroclastic flows, collections of hot volcanic ash clouds that rush down slopes. Historians believe that pyroclastic flows destroyed Pompeii. Volcanic eruptions, however, are some of the most visually astounding kinds of natural disasters.

The xylem and phloem are the two kinds of tissues that transport water and other nutrients within plants. The xylem carries water up through the plant. The phloem transports nutrients, most notably glucose, down throughout the plant.

Xylem and Phloem: The Xylem

In Classical Greek, “xylem” translates to “wood.” This makes sense, as the most common xylem tissue is wood. The xylem supply all of the parts of a plant with water by transporting water up through the plant. Xylem are long tubes called vessels. They pump water from the roots up, replacing the water that plants lose to transpiration and photosynthesis.

Xylem and Phloem: How the Xylem Transport Water

Plants depend on xylem to replace the water that evaporates off of their leaves. The xylem can transport their sap through transpirational pull. In transpirational pull, water transpires, or evaporates, off of plant surfaces into the atmosphere. As transpiration pulls water out of the plant, the water tension within the plant pulls water from the plant’s roots and soil back into the leaves. This water tension is strong enough to lift water hundreds of meters above the ground into the highest branches of trees. However, for transpirational pull to work, the xylem vessels must be very compact in diameter, as this compactness maximizes pressure.

Xylem and Phloem: Other Ways That the Xylem Transport Water

The xylem can also pull water and nutrients up through the plant via root pressure. Through osmosis, plants absorb water into their roots. This osmosis then forces sap up the xylem and into the leaves. The xylem are also aided by capillary action, the force by which water adheres to the surface of xylem pipes. This capillary action balances gravity.

Xylem and Phloem: How the Phloem Work

Phloem is the second transporting tissue in vascular plants. The phloem carry nutrients, most notably glucose, down throughout the plant. Like “xylem,” “phloem” derives from Ancient Greek. “Phloem” translates to “bar,” which makes sense, as phloem is the innermost layer of bark in trees. Phloem transport the nutrients that plants produce in photosynthesis. The phloem’s transportation is called translocation. Translocation moves the phloem’s sugar-rich sap from sugar sources to sugar sinks. Plants generally store their sugars in their roots, and the phloem transports sugar from the roots to the growing areas in the plant, the sugar sink.

Differences Between the Xylem and Phloem

The xylem and phloem both transport vital commodities through plants. However, the xylem and phloem differ in several ways. While the xylem transport mostly water, the phloem transport nutrients, especially glucose. The xylem are made up of dead cells, while the phloem are made up of living cells. Xylem only transport sap upward, while the phloem are multidirectional—they move sugars wherever they’re needed. To work, the xylem rely on water tension, while the phloem rely on translocation.

All About Bubbles

A bubble is a globule of one thermodynamic phase inside of another, like a gas in a liquid. We commonly find bubbles in boiling water, carbonated sodas, sea foam, and gas pockets in glass. Learning about bubbles can teach us about many concepts, like shape, transparency, mirrored surfaces, colors, and flexibility.

About Bubbles: How Bubbles Form

Bubbles are produced by the scientific process of nucleation. Nucleation occurs when a small pocket of one thermodynamic phase forms inside of another. In bubbles, the thermodynamic phase of a gas forms inside of the thermodynamic phase of a liquid. However, pure water is not stable enough to produce a lingering bubble. We use soap to stabilize bubbles, allowing them to linger for longer. Many incorrectly believe that soap increases water’s surface tension. This is not true. In fact, soap decreases water’s surface tension. Soap does not strengthen bubbles, it merely stabilizes them.

About Bubbles: How We Use Bubbles

We use bubbles in many ways, both practical and fun. We use bubbles in ultrasounds to help us better see babies. We use bubbles to better understand mathematical concepts, like minimal surface area. Performance artists use bubbles for their aesthetic properties. We also use bubbles as toys. Children have been playing with bubbles since the 1600s. Toy stores sell about two hundred million bottles of bubble mixture every year.

About Bubbles: Why Bubbles Pop

When disturbed, bubbles pulsate, or rapidly oscillate in size. These oscillations destabilize bubbles, leading them to eventually tear apart. The popping of bubbles below produces most of the liquid sounds that we hear.

About Bubbles: Make Your Own Bubbles

If you would like to learn more about bubbles, you can do so by observing them yourself. Enjoy educational, fun homemade bubbles by mixing your own bubble solution. Simply combine ½ a cup of dishwashing liquid, two teaspoons of sugar, and two cups of water to make bubbles whenever you want.

The Science and Story of Rainbows 

Rainbows fascinate us. We find them in nature, and then expound upon and replicate them in our religions, mythologies, literature, art, and music. In this article we will talk about the science of rainbows, our cultural perception of rainbows, and we will learn how to make a rainbow.

How to Make a Rainbow: What Is A Rainbow?

The bright rainbows that we see in the sky are “primary rainbows,” which are red on the outside of their arcs and violet on the inside. They are caused by the light that is reflected from water droplets. Although we artificially subdivide rainbows into “bands,” the colors present in rainbows are not actually separate from each other. A rainbow is a continuous spectrum of colors. Infamous “double rainbows” appear as a color-inverted second arc above a primary rainbow. Rumored “triple rainbows” are scientifically impossible and cannot naturally occur.

How to Make a Rainbow: Where Do We Find Rainbows?

We can find rainbows wherever we find sunlight shining through airborne water droplets at a low angle. We can find rainbows around rainclouds, waterfalls, and fountains. We perceive rainbows to be brightest when half of the sky is still dark with rainclouds. Sometimes, when the moon is bright enough, we can even find moonbows, or nighttime rainbows. Interestingly, one cannot actually be “under” or “at the end of” a rainbow: even if you are looking at someone who appears to be at the end of a rainbow, from their vantage point, the person sees the rainbow as being still further off yet. This means that rainbows are not actual, physical objects that we can physically approach. So much for pots of gold.

How to Make a Rainbow: Rainbows in Science

Water Clarity

When we think of oceans and lakes, we think of sparkling blue waters. However, upon closer investigation, we see that water is clear.  The reason why water is clear is that it is made up entirely of oxygen and hydrogen.  Because both of these elements are gases, their electrons are unable to absorb or reflect visible light. In fact, water refracts or changes the direction of light. For example, when a T-shirt is soaked with water, it refracts away light, making the object appear darker.  This is why absorbed water darkens material, and why water is clear.

Why Water Is Clear If Ocean and Lake Water Looks Colored

We know how and why water is clear, so it probably doesn’t make immediate sense to us that while a small amount of water is clear, lakes and oceans appear to be blue. The reason for this is that water does not absorb much light, but when it does absorb light, it absorbs red, orange and yellow light.  As a result, it reflects back the shorter blue wavelengths to observers.

Why Water Is Clear: Misleading Opacity

Large bodies of water do not always appear blue.  Many rivers can appear brown, green or even gray. These appearances can be explained by the number of dissolved or suspended particles present in water, and the depth of the water. Both particles and water depth influence how light is reflected or refracted to the observer.  Color variants arise depending on the following circumstances:

• Gray water is generally water that has been stained by runoff from parking lots, buildings and roads in urban areas.
• Brown water is colored by dissolved organic materials like plants and animals.  It is usually found in forests and wetlands.
• Green water is usually stained by suspended particles of living materials, like algae or other microscopic plants.

Why Water Is Clear: Checking for Clarity

If water is clear, there is a much better chance that it is clean.  This is why we must check whether water is turbid or hazy.  We can check water clarify with a Secchi Disk.  This instrument is a black-and-white circular plastic plate that can be lowered into water.  To use a Secchi Disk, first lower it into the water. Stop lowering it when you can’t see it anymore. Next, note the depth (in meters) off of the calibrated line. Then raise the disk back up to where it reappears, again noting the depth off of the calibrated line. Finally, add these two noted depths and divide them by two. This final value can help you gauge water’s clarity. Be sure to compare this value on a weekly basis with measurements at the same lake.

What Are Tide Pools?

Tide pools are little seawater-filled craters that form by oceans. Often these tide pools are indiscernible during the parts of the day when they are covered with seawater. They separate only at low tide, when they are revealed as microcosmic ecosystems. Naturalists and philosophers alike are fascinated by tide pools because of their scale. As John Steinbeck once wrote, “It is advisable to look from the tide pool to the stars and then back to the tide pool again.” Naturalists are also fascinated by the hardiness of the animals that live within tide pools. These animals must adapt to their environment, which changes daily.

Life in Tide Pools

Tide pool ecosystems are constantly changing. The saltiness, oxygen levels and temperature of the tide pool’s water changes every day. Because of this, only the hardiest organisms, like barnacles, can survive in tide pools. These inhabitants must survive the midday sun, big waves and predators. Tide pool creatures must be able to withstand these changing pressures. Ironically, however, they also rely on the tide pool’s changeability—their greatest danger—to survive. The fresh water provides tide pool inhabitants with fresh food sources.

Tide Pools: Microcosmic Ecosystems

Tide pools form small food chains unto themselves. Starfish eat mussels, which eat plants. Even within themselves, tide pools can be subdivided into smaller regions, or zones.

Tide Pools: The Spray Zone

The spray zone, the area highest up in the tide pool, is constantly bombarded with spray from tides and storms. This part of the tide pool is the most exposed to the elements, like the sun and winds.  For this reason, the spray zone is the most difficult area for creatures to survive. It is sparsely populated by only the hardiest creatures, like barnacles, whose impenetrable shells protect them from the elements.

Tide Pools: The High Tide Zone

The high tide zone is the part of the tide pool that is immersed in water only during high tide. While this area is easier to survive than the spray zone, the animals that live within it must still survive an ever-changing environment of waves and sunlight. In the high tide zone one can find crabs, anemones, and mussels. Although waves make life difficult in the high tide zone, they also bring food to its inhabitants.

Tide Pools: The Low Tide Zone

The low tide zone is submerged in water almost all day. This regularizes sunlight exposure and water’s saltiness and provides more shelter for the low tide zone’s dwellers. This easier survival allows for more biodiversity. The low tide zone is populated by more aquatic marine vegetation (seaweeds) than the other zones. Here one can find shrimp and sea cucumbers.

A body of water (or “water body”) is a pool of water that covers the Earth. The term “body of water” usually refers to large pools of water like seas, lakes and oceans, but it can also refer to smaller pools, like ponds, tide pools, and even puddles.

Various Bodies of Water

There are many, many different types of bodies of water. Some bodies of water occur naturally. Others, like reservoirs and harbors, are man-made. Although water formations that move around, like rivers and streams, aren’t always considered bodies of water, there is no other English term for moving bodies of water, so they are typically grouped with other bodies of water. Some bodies of water are less well-known and culturally and geographically limited in scope. For instance, the Spanish have named the “arroyo,” a creek that temporarily fills with water after a heavy rain or a rainy season. The Australians have named the “billabong,” a pool of water that forms when a river changes its course. Some major bodies of water include oceans, seas, and rivers.

Major Bodies of Water: Oceans

The largest bodies of water are oceans, enormous pools of saltwater. Oceans are continuous bodies of water that divide into smaller seas. Although interconnected, we typically describe oceans as separate. Earth’s oceans run about two miles deep. They are home to about 230,000 known marine species, and perhaps ten times that number of unknown marine species. Although interconnected into one global saltwater body that oceanographers sometimes call the “World Ocean,” Earth’s oceans are usually described as five separate bodies of water. This allows us to specify which part of the World Ocean we’re talking about. These five oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean.

Major Bodies of Water: Seas

Seas are large bodies of water that are usually connected with oceans. The term “sea” is sometimes incorrectly used as a synonym for the term “ocean.” However, oceanographers see seas and oceans as two different kinds of bodies of water. Seas are smaller saltwater bodies that are usually interconnected with oceans, but can sometimes be disconnected from oceans. For instance, the Caspian Sea is in fact a saltwater lake.

Major Bodies of Water: Rivers

Rivers are moving, usually freshwater bodies of water. They typically flow into other bodies of water, like oceans, seas, lakes, and other rivers. However, they can sometimes flow into the ground or dry up before reaching other bodies of water.

Storm surge is the coastal flooding produced by storms like tropical cyclones. Storm surge is caused by high winds that push on the ocean’s surface. These winds pile water up higher than ordinary sea levels, producing flooding.

What Is Storm Surge?

The National Hurricane Center defines storm surge as water’s height above what astronomical tide levels would predict. In layman’s terms, storm surge is the difference between how much tide we predict and how much we observe water to rise. In non-scientific contexts, people call “storm surge” “storm tide.” This term denotes the weather effects that accompany storm surge, including water rises, tide, piled-on waves, and freshwater flooding.

Storm Surge Dangers

The weather effects of storm surge are often dangerous. When people die during tropical cyclones, they typically die from surge-related conditions. Storm surge can be particularly devastating during high tide, as this makes it more difficult to predict the amount of surge that will occur. While the SLOSH (Sea, Lake, and Overland Surges from Hurricanes) model tries to predict how much storm surge a tropical cyclone will produce, weather forecasts are only accurate on short-term bases.

What Causes Storm Surge?

Storm surge is caused by environmental factors that accompany storms, including pressure, direct wind, waves, and rainfall. Tropical cyclones’ pressure raises water levels in places where there’s low atmospheric pressure. Water levels increase at downwind shores. Strong winds produce strong waves that travel in the direction that they move. Although surface waves don’t carry much water in the middle of the ocean, they can carry a lot of water to shore, and fast. Hurricanes can pour out a foot of rainfall in one day.

Storm Surge Records

The deadliest storm surge–and the deadliest natural disaster–of all time was produced by the Galveston Hurricane of 1900. When this hurricane struck Galveston, Texas, its storm surge killed nine thousand people. The highest historically noted storm surge was produced by the 1899 Cyclone Mahina in Bathurst Bay, Australia, and was noted at forty-three feet high. In the United States the highest recorded storm surge was produced by Hurricane Katrina in 2005, and was noted at twenty-five feet high.

Storm Surge Management

Places that frequently suffer from coastal flooding manage surge by monitoring it. Meteorological surveys warn us when hurricanes and severe storms are coming. In places that frequently suffer from storm surge, such as the Netherlands and the United States, people construct dams and floodgates. These storm surge barriers allow free passage when open but close when threatened with storm surge. Some communities, as in the Netherlands, create floating housing communities along wetlands. By floating, these communities can better accommodate rising tides.

The highest waterfall in the world is Angel Falls, located in the Guyana highlands of Venezuela. It plunges 979 meters, or 3,212 feet–for reference, that’s fifteen times higher than Niagara Falls. The Angel Falls comprise forty-seven drops.

The Highest Waterfall’s Surroundings

Angel Falls is located in Canaima National Park, a UNESCO World Heritage site. Canaima National Park is located in the southwest of Venezuela and to the south of the Orinoco River. The falls are deeply enmeshed in jungle and can only be reached by flight or by river trips during the rainy season. Angel Falls is dangerous to climb or descend from, as the falls create their own weather, including wind gusts and spray waves. Much of the waterfalls’ waters dissipate into mist before landing in the “Devil’s Canyon.” Those waters that do land feed into the Kerep River.

The Highest Waterfall Explored

The identity of the first European to have seen the highest waterfall is unclear. Sixteenth-century explorer Sir Walter Raleigh is widely cited as the first European to have seen Angel Falls. However, the waterfall was not widely known until Jimmy Angel’s famous 1933 flight over the waterfall in search of gold. The waterfall’s height was first officially measured by National Geographic in 1949. Today the highest waterfall is a hot tourist spot, although its summit is still difficult to reach.

The Highest Waterfall and Jimmy Angel

The highest waterfall was named in English as “Angel Falls” after Jimmy Angel, the twentieth-century explorer who was the first aviator to fly over the waterfall in a plane. Jimmy Angel’s famous flight culminated in an emergency landing atop the fall, where he abandoned his plane, trekking down the falls through the jungle for eleven days before reaching civilization. His plane remained at the top of the falls for thirty-three years, when it was brought down by helicopter. His plane is now on show in the aviation museum of Maracay.

The Highest Waterfall Renamed

The highest waterfall was in English called “Angel Falls” after Jimmy Angel, whose emergency landing atop the falls’ summit popularized the site. However, the waterfalls’ name has been disputed recently. In 2009 the Venezuelan president Hugo Chavez declared his wish to rename the waterfall with its indigenous Pemon name, “Kerepakupai Meru,” which means “waterfall of the deepest place.” Chavez later elaborated on his beliefs, saying, “This [waterfall] is ours, long before Angel ever arrived there… This is indigenous property.” Chavez later clarified that he would not enforce this name change.

What Is Water?

The chemical formula for water is H₂O. This formula means that one molecule of water is made up of to two hydrogen atoms bonded with one oxygen atom. Oxygen is a negatively charged atom and hydrogen is positively charged, but when the electrons of these atoms combine to form a water molecule, the molecule’s charge is not evenly distributed: the molecule has a slight negative charge on its oxygen end and a slight positive on its hydrogen end. Because of this, water molecules are polar. This polarity causes water molecules to be electrostatically attracted to other water molecules, and also allows water molecules to dissolve other molecules.

What is Water: Polarity’s Effects

Polarity makes water molecules special. For instance, it causes water’s solid form, ice, to float atop its liquid form, water—and unusual chemical property. This happens because water molecules’ hydrogen bonds repulse other water molecules’ hydrogen bonds, which makes the solid water molecules be spaced further apart from each other than they were as liquid water molecules. This causes ice to be less dense than water, thereby causing ice to float.

What Is Water: Other Unusual Properties

When we wonder what is water, need to understand water’s also possesses some other interesting physical properties.

• Water has strong surface tension, high heat of vaporization, and high specific heat.
• Water dissolves more substances than any other liquid, and has therefore been nicknamed “the universal solvent.”
• Water is the only chemical compound on Earth’s surface that is naturally present as liquid, gas and solid.

What is Water: Water Is Necessary for Life

All of life’s biochemical reactions rely upon liquid water to occur. Without water, the world as we know it would not exist. The world’s temperature systems would be wildly different, chemical reactions would not occur, and organisms would not be able to maintain their cell membranes. In chemical reactions, water pushes non-polar compounds together. This hydrophobia is the basis for the creation and maintenance of cell membranes, which are necessary for all living organisms. Additionally, only water can bend enzymes into the proper shape for catalyzing the chemical reactions that we need to stay alive. What is water? Necessary for life. Us folks of Operation Hydros understand how important water is, and that’s why we’re fighting so hard to conserve it.