Home » Earth Science (Page 4)
Category Archives: Earth Science
Why is the Earth still hot?
How hot is it inside of our world? Well, we see that volcanoes constantly erupts – and they have been doing do for billions of years. Evidently the interior of our planet is seething hot.
If you could have a god’s eye view of the world, see right inside it, it would look something like this:
Photo by RK (c) 2019
Wow! We can clearly see that our world’s interior is full of very hot, glowing, rock! Moving in a bit closer, we’d see hot plumes of magma slowly rising towards the surface, while cooler areas at the surface are pushed mostly sideways, and then begin to descend downwards.
This is all happening slowly of course. We’d to watch for hundreds of thousands of years to clearly see the patterns.
Questions
1. Where did all of this heat energy come from?
2. And since Earth is billions of years old, why hasn’t it cooled down yet?
1. Where did all of this heat come from?
Everything in our Solar Systems – our Sun, the Earth, and the other planets – formed from the gravitational collapse of giant molecular clouds.
Atoms and dust particles are gravitationally attracted to each other, creating larger particles, then pebble-size objects. Over time those objects collided to create rocks of various types (including organic molecules, water, and metals.)
Over longer periods of time those collided to create asteroid-size objects, and then eventually planet size objects.
Big pieces orbited around the huge center of mass, which became our star, the Sun.
Over time those bigger pieces (proto planets) swept up all the material in their path – they cleared the neighborhood of their orbit.
This process created Earth and other similar worlds: Venus, Mars, and Mercury.
We think of Earth as if it were solid, but over long time scales the interior is closer to a liquid – hotter regions expand and rise, cooler regions contract and sink.
Because of this, heavier elements, like iron, would quickly have sunk to the core. In just 10 to 100 million years. This would also pull down any other elements bound to that iron. As such, most of the Earth’s interior is metal, while most of the crust is rock.
We can see this in more detail here – the formation of our solar system
2. And since Earth is billions of years old, why hasn’t it cooled down yet?
This section includes quotes from Radioactive potassium may be major heat source in Earth’s core, Robert Sanders, UC Berkeley News, 12/13/2003
When the Earth was first formed this material was not solid; some was hot enough to become viscous (like silly putty) or even liquid (like lava.)
The denser material was mostly iron and some radioactive metals.
This dense metal slowly sank towards the center, while less dense rock floated upwards.
This process itself created a lot of friction, which created a lot of heat.
“Gradually, however, the Earth would have cooled off and become a dead rocky globe with a cold iron ball at the core if not for the continued release of heat by the decay of radioactive elements like: potassium-40, uranium-238 and thorium-232, which have half-lives of 1.25 billion, 4 billion and 14 billion years, respectively.
About one in every thousand potassium atoms is radioactive.”
Heat from the decay of radioactive elements.
Most metals we know are stable. Think of Nickel, Iron, Copper and Gold. If you put them in a box so that they don’t get exposed to oxygen, then they don’t rust, and never change. Millions of years from now they will still be around.
What’s inside metal atoms? Electrons, protons and neutrons. In a metal atom, the number of these particles will normally never change.
Example: Iron-56 26 protons, 30 neutrons, 26 electrons.
But some very large atoms are special: they not stable – they do change, all by themselves. These are called radioactive elements.
Uranium-238 92 protons, 146 neutrons, 92 electrons
-> spontaneously will change into
Plutonium-239 94 protons, 145 neutrons, 94 electrons + heat
— quote —
In sum, there was no shortage of heat in the early earth, and the planet’s inability to cool off quickly results in the continued high temperatures of the Earth’s interior.
In effect, not only do the earth’s plates act as a blanket on the interior, but not even convective heat transport in the solid mantle provides a particularly efficient mechanism for heat loss.
The planet does lose some heat through the processes that drive plate tectonics, especially at mid-ocean ridges. For comparison, smaller bodies such as Mars and the Moon show little evidence for recent tectonic activity or volcanism.
We derive our primary estimate of the temperature of the deep earth from the melting behavior of iron at ultrahigh pressures.
We know that the earth’s core depths from 2,886 kilometers to the center at 6,371 kilometers (1,794 to 3,960 miles), is predominantly iron, with some contaminants.
How? The speed of sound through the core (as measured from the velocity at which seismic waves travel across it) and the density of the core are quite similar to those seen in of iron at high pressures and temperatures, as measured in the laboratory.
Iron is the only element that closely matches the seismic properties of the earth’s core and is also sufficiently abundant present in sufficient abundance in the universe to make up the approximately 35 percent of the mass of the planet present in the core.
The earth’s core is divided into two separate regions: the liquid outer core and the solid inner core, with the transition between the two lying at a depth of 5,156 kilometers (3,204 miles).
Therefore, If we can measure the melting temperature of iron at the extreme pressure of the boundary between the inner and outer cores, then this lab temperature should reasonably closely approximate the real temperature at this liquid-solid interface.
Scientists in mineral physics laboratories use lasers and high-pressure devices called diamond-anvil cells to re-create these hellish pressures and temperatures as closely as possible.
Those experiments provide a stiff challenge, but our estimates for the melting temperature of iron at these conditions range from about 4,500 to 7,500 kelvins (about 7,600 to 13,000 degrees F).
As the outer core is fluid and presumably convecting (and with an additional correction for the presence of impurities in the outer core), we can extrapolate this range of temperatures to a temperature at the base of Earth’s mantle (the top of the outer core) of roughly 3,500 to 5,500 kelvins (5,800 to 9,400 degrees F) at the base of the earth’s mantle.
The bottom line here is simply that a large part of the interior of the planet (the outer core) is composed of somewhat impure molten iron alloy.
The melting temperature of iron under deep-earth conditions is high, thus providing prima facie evidence that the deep earth is quite hot.
Gregory Lyzenga is an associate professor of physics at Harvey Mudd College. He provided some additional details on estimating the temperature of the earth’s core:
How do we know the temperature? The answer is that we really don’t–at least not with great certainty or precision. The center of the earth lies 6,400 kilometers (4,000 miles) beneath our feet, but the deepest that it has ever been possible to drill to make direct measurements of temperature (or other physical quantities) is just about 10 kilometers (six miles).
Ironically, the core of the earth is by far less accessible more inaccessible to direct probing than would be the surface of Pluto. Not only do we not have the technology to “go to the core,” but it is not at all clear how it will ever be possible to do so.
As a result, scientists must infer the temperature in the earth’s deep interior indirectly. Observing the speed at which of passage of seismic waves pass through the earth allows geophysicists to determine the density and stiffness of rocks at depths inaccessible to direct examination.
If it is possible to match up those properties with the properties of known substances at elevated temperatures and pressures, it is possible (in principle) to infer what the environmental conditions must be deep in the earth.
The problem with this is that the conditions are so extreme at the earth’s center that it is very difficult to perform any kind of laboratory experiment that faithfully simulates conditions in the earth’s core.
Nevertheless, geophysicists are constantly trying these experiments and improving on them, so that their results can be extrapolated to the earth’s center, where the pressure is more than three million times atmospheric pressure.
The bottom line of these efforts is that there is a rather wide range of current estimates of the earth’s core temperature. The “popular” estimates range from about 4,000 kelvins up to over 7,000 kelvins (about 7,000 to 12,000 degrees F).
If we knew the melting temperature of iron very precisely at high pressure, we could pin down the temperature of the Earth’s core more precisely, because it is largely made up of molten iron.
But until our experiments at high temperature and pressure become more precise, uncertainty in this fundamental property of our planet will persist.
— end quote —
What will happen when the Earth finally cools?
When the Earth’s core finally does cool – billions of years from now – then Earth will solidify and there will be no more plate tectonics. Therefore there will be
-
No more earthquakes
-
No more volcanic eruptions
-
no more island building
-
No more mountain building
The Earth’s surface will eventually be eroded down to a flatter surface, marred only by new impact craters.
Earth will then be a geologically dead planet, like the Moon.
Some scientists estimate that “The planet is now cooling about 100°C every 1 billion years, so eventually, maybe several billions of years from now, the waning rays of a dying sun will shine down on a tectonically dead planet whose continents are frozen in place.”
How do we know what lies at the Earth’s core?
How we know what lies at the Earth’s core. BBC
Addressing misconceptions
If the Earth’s core is radioactive why is there no radiation at the surface?
Click the link to read the article, but short version, there indeed is radioactivity here on the Earth’s surface!
External resources and discussions
What percent of the Earth’s core is uranium? earthscience.stackexchange.com
Claim: Radioactive decay accounts for half of Earth’s heat, and related, What Keeps the Earth Cooking? Berkeley Lab scientists join their KamLAND colleagues to measure the radioactive sources of Earth’s heat flow
A fascinating although somewhat controversial article, Andrault, Denis & Monteux, J. & Le Bars, Michael & Samuel, H.. (2016). The deep Earth may not be cooling down. Earth and Planetary Science Letters. 443. 10.1016/j.epsl.2016.03.020.
_________________________________________
This website is educational. Materials within it are being used in accord with the Fair Use doctrine, as defined by United States law.
§107. Limitations on Exclusive Rights: Fair Use. Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phone records or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use, the factors to be considered shall include: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and the effect of the use upon the potential market for or value of the copyrighted work. (added pub. l 94-553, Title I, 101, Oct 19, 1976, 90 Stat 2546)
Tidal water level changes in the Merrimack River
I knew about significant water level changes, due to the tides, out at the mouth of the Merrimack River, Massachusetts, but didn’t realize that they were so effective when miles inland. So when I heard that the water levels in Haverhill would be low, I had to take a drive out to the river to see what it would be like.
So here I am, after I walked out into the middle of the river! GPS clearly shows how far I walked out.
I just looked at the NOAA (National Oceanic and Atmospheric Administration) Tides and Current pages for Newburyport, MA, Merrimack River, Station ID: 8440466
tidesandcurrents.noaa.gov, 8440466
This graph shows the significant differences between the river level at high and low tide, where the Merrimack meets the Atlantic Ocean, in Newburyport.
So now I am looking here, likely close to where I was standing in Haverhill, Riverside, Merrimack River, – Station ID: 8440889
tidesandcurrents.noaa.gov, 8440889
This graph shows the differences between the river level at high and low tide, further upriver, in Haverhill, MA.
This brings up the question, how are the tides created? Check out our resource, the origin of tides.
Beach in the UK
Origin of the oceans
The origin of water on Earth is studied by scientists in planetary science, astronomy, and astrobiology.
Earth is unique among the rocky planets in the Solar System in that it is the only planet known to have oceans of liquid water on its surface.
Liquid water, necessary for life as we know it, exists on the surface of Earth because we are far enough from the Sun to avoid a runaway greenhouse effect, but not so far that low temperatures cause all water on the planet to freeze.
Where did our water oceans come from? Many people hypothesized that water and other volatiles must have been delivered to Earth from the outer Solar System later in its history. Recent research, however, indicates that hydrogen inside the Earth played a role in the formation of the ocean.
The two ideas are not mutually exclusive, as there is also evidence water was delivered to Earth by impacts from icy planetesimals similar in composition to asteroids in the outer edges of the asteroid belt.
This introduction excerpted and adapted from Origin of water on Earth, Wikipedia.
What the surface of Earth likely looked like when it was around one billion years old. It is presently 4.5 billions years old.
There is at least an ocean’s worth of water molecules trapped underground, deep within the earth’s crust.
Much water may have been brought to earth by comets and water-rich asteroids.
Large amounts of water are bound up with other minerals, under the surface of the Earth.
More TBA
Packet
Packet (Word document) How the ocean came to be
Astrooceanography
The study of oceans outside planet Earth. Unlike other planetary sciences like astrobiology, astrochemistry and planetary geology, it only began after the discovery of underground oceans in Saturn’s Titan and Jupiter’s Ganymede.
This field remains speculative until further missions reach the oceans beneath the rock or ice layer of the moons.
There are many theories about oceans or even ocean worlds of celestial bodies in the Solar System, from oceans made of diamond in Neptune to a gigantic ocean of liquid hydrogen that may exist underneath Jupiter’s surface.
Early in their geologic histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, and a runaway greenhouse effect may have boiled away the global ocean of Venus.
Unconfirmed oceans are speculated beneath the surface of many dwarf planets and natural satellites; notably, the ocean of the moon Europa is estimated to have over twice the water volume of Earth.
Also see Extraterrestrial liquid water
This section excerpted from Astrooceanography, Wikipedia
Research
Ancient Earth was a water world, Paul Voosen, Science (magazine) 3/9/2021
External articles
The Guardian, Earth-may-have-underground-ocean-three-times-that-on-surface
Extremetech.com, An ocean-400-miles-beneath-our-feet-that-could-fill-our-oceans-three-times-over
Water-rich gem points to vast ‘oceans’ beneath Earth’s surface, study suggests
.
The water cycle and atmospheric rivers
From NOAA, National Oceanic and Atmospheric Administration
The water cycle is often taught as a simple circular cycle of evaporation, condensation, and precipitation.
Although this can be a useful model, the reality is much more complicated. The paths and influences of water through Earth’s ecosystems are extremely complex and not completely understood.
Image from NOAA, National Oceanic and Atmospheric Administration
Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow.
Water in different phases moves through the atmosphere (transportation).
Liquid water flows across land (runoff), into the ground (infiltration and percolation), and through the ground (groundwater).
Groundwater moves into plants (plant uptake) and evaporates from plants into the atmosphere (transpiration).
Solid ice and snow can turn directly into gas (sublimation).
The opposite can also take place when water vapor becomes solid (deposition).
Atmospheric river
Atmospheric rivers are relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics.
These columns of vapor move with the weather, carrying an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi River. When the atmospheric rivers make landfall, they often release this water vapor in the form of rain or snow.
Although atmospheric rivers come in many shapes and sizes, those that contain the largest amounts of water vapor and the strongest winds can create extreme rainfall and floods, often by stalling over watersheds vulnerable to flooding.
These events can disrupt travel, induce mudslides and cause catastrophic damage to life and property.
A well-known example is the “Pineapple Express,” a strong atmospheric river that is capable of bringing moisture from the tropics near Hawaii over to the U.S. West Coast.
Not all atmospheric rivers cause damage; most are weak systems that often provide beneficial rain or snow that is crucial to the water supply. Atmospheric rivers are a key feature in the global water cycle and are closely tied to both water supply and flood risks — particularly in the western United States.
.
Protecting New Orleans from rising water levels
New Orleans, Louisiana
This is a placeholder blogpost. The article is to be written
Map: Google Maps. Photos by Mary Grace McKernan; infographic: by Marc Fusco.
.
Image by Midnightcomm for Wikipedia, public domain.
.
Apps & Interactive graphics
Louisiana’s Sea Level Is Rising: SeaLevelRise.org
.
Articles
Fortified But Still In Peril, New Orleans Braces for Its Future: In the years after Hurricane Katrina, over 350 miles of levees, flood walls, gates and pumps came to encircle greater New Orleans. Experts say that is not enough.
By John Schwartz and Mark Schleifstein, 2/24/2018
Fortified But Still In Peril, New Orleans Braces for Its Future
After a $14-Billion Upgrade, New Orleans’ Levees Are Sinking. Sea level rise and ground subsidence will render the flood barriers inadequate in just four years. By Thomas Frank, E&E News, Scientific American, 4/11,/2019
After a $14-Billion Upgrade, New Orleans’ Levees Are Sinking. Scientific American
Rising Sea Levels May Limit New Orleans Adaptation Efforts. New Orleans sees that even modern engineering cannot eliminate flooding risk. By Emily Holden, ClimateWire on September 10, 2015. Scientific American.
Rising Sea Levels May Limit New Orleans Adaptation Efforts. Scientific American
Fortified but still in peril, New Orleans braces for its future: Our Drowning Coast. By Mark Schleifstein | Posted February 24, 2018.
Fortified but still in peril, New Orleans braces for its future
Rising sea to displace 500,000 New Orleans area residents, study says; see where they might go. By Tristan Baurick, NOLA.com | The Times-Picayune. 4/20/2017.
A study published this week (April 2017) predicts that sea level rise will push hundreds of thousands of people out of U.S. coastal cities such as New Orleans. It says the population will boom in nearby inland cities such as Austin. The University of Georgia study is considered the first detailed look at how inland cities might be affected by sea level rise. It estimates more than than 500,000 people will flee the seven-parish New Orleans area by 2100 due to sea level rise and the problems that come with it, including frequent flooding and greater exposure to storm surges. That’s more than one third of metro New Orleans’s current population…. Across the United States, the study estimates, 13 million people will be displaced by sea level rise under a scenario in which some efforts are taken to mitigate the impacts of sea level rise. The biggest draw, it predicts, will be Austin, gaining 600,00 to 800,000 people on top of the metro area’s current estimated population of 2.1 million. Other inland cities likely to grow substantially include Orlando, Fla., Atlanta and Phoenix.
Rising sea to displace 500,000 New Orleans area residents, study says. NOLA.com
Migration induced by sea-level rise could reshape the US population landscape
Mathew E. Hauer. Nature Climate Change volume 7, pages 321–325 (2017)
Many sea-level rise (SLR) assessments focus on populations presently inhabiting vulnerable coastal communities, but to date no studies have attempted to model the destinations of these potentially displaced persons. With millions of potential future migrants in heavily populated coastal communities, SLR scholarship focusing solely on coastal communities characterizes SLR as primarily a coastal issue, obscuring the potential impacts in landlocked communities created by SLR-induced displacement. Here I address this issue by merging projected populations at risk of SLR with migration systems simulations to project future destinations of SLR migrants in the United States. I find that unmitigated SLR is expected to reshape the US population distribution, potentially stressing landlocked areas unprepared to accommodate this wave of coastal migrants—even after accounting for potential adaptation. These results provide the first glimpse of how climate change will reshape future population distributions and establish a new foundation for modelling potential migration destinations from climate stressors in an era of global environmental change.
What did Earth look like millions of years ago?
Ever wonder what the Earth looked like before humans came along?
The 3D interactive website called Ancient Earth Globe lets you glimpse the world from space during the age of the dinosaurs — and more. Seeing the Earth at various points in geological history, from 750 million years ago to today, is an eye-opening activity to say the least. The website allows you to see the entire globe as it slowly rotates, or zoom in to see closer details of land and oceans. There’s also an option to remove clouds for an even better look.
(Text by Bonnie Burton, Cnet, 8/7/18, See what Earth looked like from space when it was ruled by dinosaurs)
Sea level rise
Should we be worried about surging Antarctic ice melt and sea level rise?
Dana Nuccitelli, The Guardian, 18 Jun 2018
There’s recently been a spate of sea level rise denial in the conservative media, but in reality, sea level rise is accelerating and melting ice is playing an increasingly large role. In the first half of the 20th Century, average global sea level rose by about 1.4 millimeters per year (mm/yr). Since 1993, that rate has more than doubled to 3.2 mm/yr. And since 2012, it’s jumped to 4.5 mm/yr.
Global mean sea level data from the Colorado University Sea Level Research Group, with 4-to-5-year linear trends shown in black and red. Illustration: Dana Nuccitelli
Thermal expansion (ocean water expanding as it warms) continues to play the biggest role in sea level rise, but its contribution of about 1.3 mm/yr is now responsible for a smaller proportion of total sea level rise (30% in recent years) than its contribution since the 1990s (40% of the total). That’s because of the acceleration in melting ice.
Glacier melt is accelerating, recently contributing about 0.75 mm/yr to sea level rise, up from 0.65 mm/yr since the 1990s. But the biggest jumps have come from ice in Greenland and Antarctica. Greenland had been responsible for about 0.48 mm/yr sea level rise since 1990, but in recent years is up to 0.78 mm/yr. A recent study in Nature Climate Change found that Greenland contributed about 5% to sea level rise in 1993 and 25% in 2014.
Antarctica is a huge question mark with warning signs
A new study published in Nature using data from a range of satellites found that Antarctica’s contribution has tripled from about 0.2 mm/yr since the 1990s to 0.6 mm/yr since 2012, during which time global sea level rise also spiked. Accelerated ice melt from Antarctica, Greenland, and glaciers have all played a role in the faster recent sea level rise. The question is whether it’s a temporary jump, or if we need to worry about a continued acceleration in Antarctic ice loss.
Another recent paper published in Earth’s Future found that rapid losses from Antarctic ice are plausible. The study found that in moderate to high carbon-emission scenarios, an average expected sea level rise of 2 to 2.5 feet by 2100 could actually become 3 to 5 feet once Antarctic ice sheet dynamics are taken into account.
The vast majority of Antarctica’s current ice loss is coming from West Antarctica, where about 75% of the glaciers are located below sea level. In East Antarctica, which has so far remained stable, only about 35% of the glaciers are below sea level. Warming ocean waters are melting the Antarctic ice from below, which is particularly problematic for that low-lying ice in West Antarctica. Research suggests that the collapse of the Western Antarctic ice sheet is already unstoppable.
The amount of ice loss across Antarctica in total (purple), and in West Antarctica (green), East Antarctica (yellow) and the Antarctic Peninsula (red). Illustration: Shepherd et al. (2018), Nature
Should we be worried?
Short term variations in sea level rise do happen. Sea level actually briefly fell in 2010 due to a strong La Niña cycle, which typically results in an increase of rain and snow falling over land. This resulted in a number of epic deluges and flooding across the globe; more water on land temporarily meant less in the ocean.
However, Antarctica and Greenland could potentially cause rapid sea level rise. As James Hansen explains in the video below, there have been periods in the not-so-distant past when sea levels rose at an average rate of 1 meter every 20 years.
In past eras when temperatures and atmospheric carbon dioxide levels were similar to those today and to the Paris climate targets, like in the last interglaciation and the Pliocene, sea levels were about 20 to 80 feet higher. Unless we manage to actually cool global temperatures, we’re certainly due for significantly more sea level rise. The large ice sheets on Greenland and Antarctica will continue to melt for as long as 1,000 years. That’s why sea levels were so much higher in past eras whose climates remained at hot temperatures like today’s for thousands of years.
It takes time for ice to melt. The question is, how fast will it happen? Sea level rise unquestionably poses a long-term threat, but how much of a short-term threat largely depends on just how stable the Antarctic ice sheet turns out to be. The recent acceleration of Antarctic ice loss, while not yet definitive, is certainly cause for concern.
________________________________
This website is educational. Materials within it are being used in accord with the Fair Use doctrine, as defined by United States law.
§107. Limitations on Exclusive Rights: Fair Use. Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phone records or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use, the factors to be considered shall include: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and the effect of the use upon the potential market for or value of the copyrighted work. (added pub. l 94-553, Title I, 101, Oct 19, 1976, 90 Stat 2546)
Facts and Fiction of the Schumann Resonance
This has been excerpted from Facts and Fiction of the Schumann Resonance,by Brian Dunning, Skeptoid Podcast #352
It’s increasingly hard to find a web page dedicated to the sales of alternative medicine products or New Age spirituality that does not cite the Schumann resonances as proof that some product or service is rooted in science. … Today we’re going to see what the Schumann resonances actually are, how they formed and what they do, and see if we can determine whether they are, in fact, related to human health.
In physics, Schumann resonances are the name given to the resonant frequency of the Earth’s atmosphere, between the surface and the densest part of the ionosphere.
Image from nasa.gov/mission_pages/sunearth/news/gallery
They’re named for the German physicist Winfried Otto Schumann (1888-1974) who worked briefly in the United States after WWII, and predicted that the Earth’s atmosphere would resonate certain electromagnetic frequencies.
[What is a resonant frequency? Here is a common example. When you blow on a glass bottle at a certain frequency, you can get the bottle to vibrate at the same frequency]
from acs.psu.edu/drussell/Demos/BeerBottle/beerbottle.html
This glass bottle has a resonant frequency of about 196 Hz.
That’s the frequency of sound waves that most efficiently bounce back and forth between the sides of the bottle, at the speed of sound, propagating via the air molecules.
Electromagnetic radiation – like light, and radio waves – is similar, except the waves travel at the speed of light, and do not require a medium like air molecules.
The speed of light is a lot faster than the speed of sound, but the electromagnetic waves have a lot further to go between the ground and the ionosphere than do the sound waves between the sides of the bottle.
This atmospheric electromagnetic resonant frequency is 7.83 Hz, which is near the bottom of the ELF frequency range, or Extremely Low Frequency.
The atmosphere has its own radio equivalent of someone blowing across the top of the bottle: lightning.
Lightning is constantly flashing all around the world, many times per second; and each bolt is a radio source. This means our atmosphere is continuously resonating with a radio frequency of 7.83 Hz, along with progressively weaker harmonics at 14.3, 20.8, 27.3 and 33.8 Hz.
These are the Schumann resonances.
It’s nothing to do with the Earth itself, or with life, or with any spiritual phenomenon;
it’s merely an artifact of the physical dimensions of the space between the surface of the Earth and the ionosphere.
Every planet and moon that has an ionosphere has its own set of Schumann resonances defined by the planet’s size.
Biggest point: this resonated radio from lightning is a vanishingly small component of the electromagnetic spectrum to which we’re all naturally exposed.
The overwhelming source is the sun, blasting the Earth with infrared, visible light, and ultraviolet radiation.
All natural sources from outer space, and even radioactive decay of naturally occurring elements on Earth, produce wide-spectrum radio noise. Those resonating in the Schumann cavity are only a tiny, tiny part of the spectrum.
Nevertheless, because the Schumann resonance frequencies are defined by the dimensions of the Earth, many New Age proponents and alternative medicine advocates have come to regard 7.83 Hz as some sort of Mother Earth frequency, asserting the belief that it’s related to life on Earth.
The most pervasive of all the popular fictions surrounding the Schumann resonance is that it is correlated with the health of the human body.
There are a huge number of products and services sold to enhance health or mood, citing the Schumann resonance as the foundational science.
A notable example is the Power Balance bracelets. Tom O’Dowd, formerly the Australian distributor, said that the mylar hologram resonated at 7.83 Hz.
When the bracelet was placed within the body’s natural energy field, the resonance would [supposedly] “reset” your energy field to that frequency.
Well, there were a lot of problems with that claim.
First of all, 7.83 Hz has a wavelength of about 38,000 kilometers. This is about the circumference of the Earth, which is why its atmospheric cavity resonates at that frequency. 38,000 kilometers is WAY bigger than a bracelet!
There’s no way that something that tiny could resonate such an enormous wavelength. O’Dowd’s sales pitch was implausible, by a factor of billions, to anyone who understood resonance.
This same fact also applies to the human body. Human beings are so small, relative to a radio wavelength of 38,000 kilometers, that there’s no way our anatomy could detect or interact with such a radio signal in any way.
Proponents of binaural beats cite the Schumann frequency as well. These are audio recordings which combine two slightly offset frequencies to produce a third phantom beat frequency that is perceived from the interference of the two.
Some claim to change your brain’s encephalogram, which they say is a beneficial thing to do. Brain waves range from near zero up to about 100 Hz during normal activity, with a typical reading near the lower end of the scale.
This happens to overlap 7.83 — suggesting the aforementioned pseudoscientific connection between humans and the Schumann resonance — but with a critical difference. An audio recording is audio, not radio. It’s the physical oscillation of air molecules, not the propagation of electromagnetic waves. The two have virtually nothing to do with each other.
[Other salespeople claim] that our bodies’ energy fields need to interact with the Schumann resonance, but can’t because of all the interference from modern society [and so they try to sell devices that supposedly connect our body to the Schumann resonance.]
It’s all complete and utter nonsense. Human bodies do not have an energy field: in fact there’s not even any such thing as an energy field. Fields are constructs in which some direction or intensity is measured at every point: gravity, wind, magnetism, some expression of energy.
Energy is just a measurement; it doesn’t exist on its own as a cloud or a field or some other entity. The notion that frequencies can interact with the body’s energy field is, as the saying goes, so wrong it’s not even wrong.
Another really common New Age misconception about the Schumann resonance is that it is the resonant frequency of the Earth. But there’s no reason to expect the Earth’s electromagnetic resonant frequency to bear any similarity to the Schumann resonance.
Furthermore, the Earth probably doesn’t even have a resonant electromagnetic frequency. Each of the Earth’s many layers is a very poor conductor of radio; combined all together, the Earth easily absorbs just about every frequency it’s exposed to. If you’ve ever noticed that your car radio cuts out when you drive through a tunnel, you’ve seen an example of this.
Now the Earth does, of course, conduct low-frequency waves of other types. Earthquakes are the prime example of this. The Earth’s various layers propagate seismic waves differently, but all quite well. Seismic waves are shockwaves, a physical oscillation of the medium. Like audio waves, these are unrelated to electromagnetic radio waves.
Each and every major structure within the Earth — such as a mass of rock within a continent, a particular layer of magma, etc. — does have its own resonant frequency for seismic shockwaves, but there is (definitively) no resonant electromagnetic frequency for the Earth as a whole.
So our major point today is that you should be very skeptical of any product that uses the Schumann resonance as part of a sales pitch.
The Earth does not have any particular frequency. Life on Earth is neither dependent upon, nor enhanced by, any specific frequency.
Source: skeptoid.com/episodes/4352
If we assume global warming is a hoax, what should we expect to see
This analysis is by Phil Plait, Mar 9, 2017
I will ask you to indulge me for a moment in a thought experiment. It’s not hard, and it leads to a startlingly simple yet powerful conclusion, one I think you may find both important and terribly useful.
Still, it starts with a big ask, so forgive me. And that is: Let’s make an assumption, one you’ve heard many times before. Let’s say that global warming is a hoax.
I know, I know. But go with this, here. So, yes, let’s say that climate change deniers —people like House Science, Space, and Technology Committee chairman Lamar Smith, Senator James Inhofe, and even Donald Trump himself— are right. Whatever the reasons (Chinese hoax, climatologist cabal clamoring colossal cash, carbon dioxide isn’t a powerful greenhouse gas, or just a liberal conspiracy), let’s say that the Earth is not warming up.
In that case, the temperatures we see today on average should be much like the ones we saw, say, 20 years ago. Or 50. Sure, you’d see fluctuations. In a given spot on a given day the temperature in 1968 might have been a degree warmer than it was in 1974, or three degrees cooler than in 2010. But what you’d expect is that over time, a graph showing the temperature would be pretty much flat, with lots of short-term spikes up and down.
Now, statistically speaking, you expect some records to be broken every now and again. Over time, every few years for a given day you’d get a record high, and every few years a record low. The details will change from place to place and time to time, but again, if the average temperature trend is flat, unchanging, then you would expect to see just as many record cold days as record warm days. There might be small deviations, like, say, a handful of more cool than warm days, but the difference would be very small depending on how many days you look at.
It’s like flipping a coin. On average, you should get a 50/50 split between heads and tails. But if you flip it 10 times, say, you wouldn’t be shocked to see seven heads and three tails. But if you flip it a thousand times, you’d really expect to see a very even split. Seeing 700 heads and 300 tails would be truly extraordinary.
So, if we remind ourselves of our basic assumption —global warming isn’t real— then we expect there to be as many record high days as there are record lows. Simple statistics.
So, what do we see?
Guy Walton, a meteorologist in Georgia, took a look at the data from the NOAA’s National Centers for Environmental Information. Whenever a weather station in the US breaks a record, high or low, it’s catalogued (Walton has more info on this at the link above). He found something astonishing: For February 2017, the number of record highs across the US recorded was 6,201.
The number of record lows? 128.
That’s a ratio of over 48:1. In just one month.
Again, if temperatures were flat over time, and record highs and lows were random fluctuations, you’d expect a ratio much closer to 1:1. In other words, out of 6329 records set in total, you’d expect there to be about 3165 record highs, and 3165 record lows.
For fans of statistics, with a total of 6329 records broken, one standard deviation is the square root of that, or about 80. So, sure, something like 3265 highs and 3064 lows wouldn’t be too unusual. If you start to see more of an imbalance than that, it would be weird.
Seeing 6201 record highs to 128 lows is very, very, very weird. Like, zero chance of that happening by accident.
Now, Phil, I can hear you thinking, that’s just for the US (2% of the planet) over one month. And you’ve told us before that weather isn’t climate; weather is what you expect now, climate is what you expect over long periods of time. So, maybe this is a fluke?
Walton notes that, if you look at records in the US going back to the 1920s, the six highest ratios of record highs to lows all occur since the 1990s. Huh.
And making this more global, a pair of Australian scientists looked at their country’s data, and found that their ratios were about even…until the 1960s. After that, highs always outnumber lows. From 2000-2014, record highs outnumbered lows there by 12:1.
The University Corporation for Atmospheric Research collated data from 1800 stations across the US and binned the data by decade — by decade, which is a huge sample; any deviation from a 1:1 ratio would be extraordinary over that timescale.
This graphic shows the ratio of record daily highs to record daily lows observed at about 1,800 weather stations in the 48 contiguous United States from January 1950 through September 2009. Each bar shows the proportion of record highs (red) to record lows (blue) for each decade. The 1960s and 1970s saw slightly more record daily lows than highs, but in the last 30 years record highs have increasingly predominated, with the ratio now about two-to-one for the 48 states as a whole. (©UCAR, graphic by Mike Shibao.)
Source of the above image: RECORD HIGH TEMPERATURES FAR OUTPACE RECORD LOWS ACROSS U.S. The National Center for Atmospheric Research/UCAR, Nov 12, 2009
We are seeing far more record high temperatures than record lows in the US… and in other countries, too. Credit: UCAR
Huh. Not only are there more record highs than lows, the ratio between the two is getting higher with time.
So, looking back at our initial assumption — the Earth isn’t warming, and temperatures are flat— there’s a conclusion these data are screaming at us: That assumption is completely and utterly wrong.
And of course, all the evidence backs this up. All of it. Earth’s temperature is increasing. That’s because of the 40 billion tons of extra carbon dioxide humans put into the atmosphere every year (the amount we will see this year, expected to top 410 parts per million, has never been seen before in history as long as humans have walked the Earth). This CO2 allows sunlight to warm the Earth, but prevents all of it from escaping so that a little bit of extra heat remains behind, and that’s warming our planet.
Over time, we’re getting hotter. 2014 was a record hot year, beaten by 2015, itself beaten by 2016. In fact, 15 of the 16 hottest years ever recorded have been from 2001 – 2016. That’s exactly what you’d expect if we were getting warmer, and that means our initial assumption of hoaxery was dead wrong.
The science on this is so basic, the evidence of this so overwhelming, that “not a single national science academy disputes or denies the scientific consensus around human-caused climate change”, and also the overwhelming majority of scientists who study climate do, too.
Maybe you should listen to them, and not politicians who seem ideologically opposed to the science.
Or, you could flip a coin. But if it comes up science dozens of times more often than anti-science, well —and forgive me if I sound like a broken record— the conclusion is obvious.
___________________________
Fair use: This website is educational. Materials within it are being used in accord with the Fair Use doctrine, as defined by United States law.
§107. Limitations on Exclusive Rights: Fair Use
Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phone records or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use, the factors to be considered shall include: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and the effect of the use upon the potential market for or value of the copyrighted work. (added pub. l 94-553, Title I, 101, Oct 19, 1976, 90 Stat 2546)
Protecting cities from rising sea levels
Protecting cities from rising sea levels
from “Can New York Be Saved in the Era of Global Warming?” by Jeff Goodell, Rolling Stone, July 2016.
Hurricane Sandy, which hit New York in October 2012, flooding more than 88,000 buildings in the city and killing 44 people, was a transformative event. It did not just reveal how vulnerable New York is to a powerful storm, but it also gave a preview of what the city faces over the next century, when sea levels are projected to rise five, six, seven feet or more, causing Sandy-like flooding (or much worse) to occur with increasing frequency.
Credit – Jamal Countess/Redux
Zarrilli turns away from the river, and we walk toward the park that separates it from the Lower East Side. “One of our goals is not just to protect the city, but to improve it,” Zarrilli explains. Next year, if all goes well, the city will break ground on what’s called the East Side Coastal Resiliency Project, an undulating 10-foot-high steel-and-concrete-reinforced berm that will run about two miles along the riverfront. It’s the first part of a bigger barrier system, known informally as “the Big U,” that someday may loop around the entire bottom of Manhattan… there are plans in the works to build other walls and barriers in the Rockaways and on Staten Island, as well as in Hoboken, New Jersey, across the Hudson River. …
…wall-building is politically fraught: You can’t wall off the city’s entire 520-mile coastline, so how do you decide who gets to live behind the wall and who doesn’t? “You have to start somewhere,” Zarrilli says, “so you begin in the places where you get the maximum benefit for the most people.”
In Zarrilli’s view, there is no time to waste. By 2030 or so, the water in New York Harbor could be a foot higher than it is today. That may not sound like much, but New York does not have to become Atlantis to be incapacitated. Even with a foot or two of sea-level rise, streets will become impassable at high tide, snarling traffic. …
Then the big storm will come… if you add a foot or two of sea-level rise to a 14-foot storm tide, you have serious trouble. …Water will flow over the aging sea walls at Battery Park and onto the West Side, pouring into the streets, into basements, into cars, into electrical circuits, finding its way into the subway tunnels. New Yorkers will learn that even after the region spent $60 billion on rebuilding efforts after Sandy, the city’s infrastructure is still hugely vulnerable.
… New York’s Achilles’ heel is the subways, which are vulnerable to saltwater, which is highly corrosive to electrical circuits, as well as to the concrete in the tunnels. In theory, the subway system can be restructured to keep seawater out, but at some point, the cost gets prohibitive. … the Metropolitan Transportation Authority, which operates the New York subways, had to spend $530 million upgrading the South Ferry station in Lower Manhattan after it was heavily damaged on 9/11. After Sandy turned the station into a fish tank, the MTA had to close it for months and spend another $600 million to fix it. The MTA has now installed retractable barriers to stop seawater from flooding the station in the next big storm, but the subway system remains vulnerable to rising seas. “We’re not thinking systemically about climate change,” says Michael Gerrard, director of the Center for Climate Change Law at Columbia Law School. “We’re focused on Sandy, and Sandy isn’t the worst thing that could happen.”
In the end, there is only one real solution for sea-level rise: moving to higher ground.
In the near future, one of the main drivers of what policy wonks call “managed retreat” is likely to be the rising costs of flood insurance, which is provided to most property owners through National Flood Insurance Protection, an outdated, mismanaged federal program that subsidizes insurance rates for homeowners and businesses in high-risk areas (commercial insurers bailed out of the flood-insurance market decades ago).
Under NFIP, few people who live in flood-prone areas pay the actual cost of the risk. In addition, grandfather clauses in the program often allow homeowners to rebuild in areas that are doomed to flood again very soon. Attempts by Congress to reform the program have failed miserably, and it’s now $23 billion in debt. Eventually, increasing property losses will force reform and insurance rates will go up and up. “When people have to pay more and own more of the risk themselves, their decisions about where they live will change,” says Alex Kaplan, a senior vice president at Swiss Re, a global reinsurance company.
New York state is already experimenting with voluntary buyouts in high-risk areas. The logic is simple: In the long run, it’s cheaper simply to buy people out of their homes than to keep paying for them to be rebuilt after storms (it also moves people out of harm’s way).
Of course, it would cost hundreds of billions of dollars to buy out residents and businesses in Lower Manhattan. Instead, some urban planners have discussed offering tax breaks and other financial goodies to encourage residents and businesses to relocate to higher ground. Could parts of Lower Manhattan ever be de-populated and returned to nature? “Buildings were built,” says Kate Orff, director of the urban-planning program at Columbia University’s Graduate School of Architecture, Planning and Preservation. “They can also be unbuilt.” More likely, the walls will go up, getting higher and higher as the seas rise.
The above info is from https://www.rollingstone.com/politics/news/can-new-york-be-saved-in-the-era-of-global-warming-20160705#ixzz4Da26LKLM
Protecting Staten Island, New York City
Topic: Staten Island Multi-Use Elevated Promenade
This text from the article “A 5.3-Mile “Elevated Promenade” On Staten Island Will Break Ground This Year” by Bianca Bahmondes, Secret NYC, 2/25/2019
It was recently announced that the 5.3-mile proposed seawall in Staten Island will officially begin construction since federal funding has now been secured. The U.S. Army Corps for Engineers (USACE) will be giving $400 million to the project, which is formally known as the Staten Island Multi-Use Elevated Promenade. This new promenade has been in the works since 2015 and is intended to help protect the island from sea-level rising, storm surges, and super storms in the future.
It will be build along the island’s eastern coast from Fort Wadsworth to Great Kills. The promenade will rise about 20 feet above sea level and feature a series of interconnected leaves, berms, and seawalls that are designed to withstand a 300-year storm.
In the announcing statement Governor Cuomo said: “This innovative project will protect Staten Islanders from future devastating storms, enhance access to the shore, create thriving wetlands and bring peace of mind to the diverse communities that live along the coastline. [This] agreement allows New York to move forward with this critical resiliency measure, which will ensure vulnerable communities have the resources they need to build back stronger after the devastation of Hurricane Sandy and better prepare for the next 100-year storm.”
Images from https://www.governor.ny.gov/sites/governor.ny.gov/files/atoms/files/Visualization.pdf
Further reading
tba
Learning Standards
2016 Massachusetts Science and Technology/Engineering Curriculum Framework
HS-ESS2-6. Use a model to describe cycling of carbon through the ocean, atmosphere, soil, and biosphere and how increases in carbon dioxide concentrations due to human activity have resulted in atmospheric and climate changes.
HS-ESS3-1. Construct an explanation based on evidence for how the availability of key natural resources and changes due to variations in climate have influenced human activity.
HS-LS2-7. Analyze direct and indirect effects of human activities on biodiversity and ecosystem health, specifically habitat fragmentation, introduction of non-native or invasive species, overharvesting, pollution, and climate change. Evaluate and refine a solution for reducing the impacts of human activities on biodiversity and ecosystem health.*
High School Technology/Engineering
HS-ETS1-1. Analyze a major global challenge to specify a design problem that can be improved. Determine necessary qualitative and quantitative criteria and constraints for
solutions, including any requirements set by society.*
HS-ETS1-2. Break a complex real-world problem into smaller, more manageable problems that each can be solved using scientific and engineering principles.*
HS-ETS1-3. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, aesthetics, and maintenance, as well as social, cultural, and environmental impacts.*
KaiserScience 