Sound on EARTH Magazine

Red Planet Roundup: March 2019

Wed, 13 Feb 2019 16:34:23 -0500

The pale green regions in this map of Gale Crater geology are portions of the Hummocky Plains Unit, which contains conglomerate rock strata featuring large cross beds and ridges that researchers think were formed by glacial outburst flooding. Credit: Ezat Heydari et al., GSA Meeting, November 2018.

With two rovers and a lander on the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

Ecuadorian volcano plays its pipe

Mon, 10 Sep 2018 11:44:11 -0400

The once-visible floor of Cotopaxi's summit crater dropped out of sight after the 2015 eruptions. Credit: both: Silvia Vallejo Vargas/Instituto Geofisico, Escuela Politécnica Nacional.

An active volcano in central Ecuador may be the largest musical instrument on Earth: After eruptions in 2015, Cotopaxi’s newly configured crater started emitting distinctly musical rumblings that scientists may be able to use to monitor future activity at the volcano.

Why meteors snap, crackle and pop

Wed, 09 Aug 2017 16:40:02 -0400

A meteor streaks through the night sky over South Australia. Credit: C m handler, CC BY-SA 3.0.

Keen-eared observers sometimes report hearing popping, whistling or buzzing at the same time they see meteors pass far overhead, a perplexing phenomenon called the electrophonic effect. What causes the effect — or if it’s even real — has been discussed for centuries; famed astronomer Edmond Halley is said to have dismissed it as a figment of people’s imaginations. In a new study in Geophysical Research Letters, researchers suggest that not only is it real, but that it is caused by radio waves induced by meteors and converted to sound waves near Earth’s surface.

Source of Red Sea's mysterious cannon earthquakes revealed

Mon, 21 Sep 2015 11:16:00 -0400

Cannon-like blasts sometimes accompany small earthquakes in the Abu Dabbab region of Egypt along the coast of the Red Sea. Credit: Marc Ryckaert, CC BY 3.0.

For decades, people living along Egypt’s Red Sea coast have reported hearing loud blasts accompanying the small earthquakes that regularly jolt the Abu Dabbab region. And there is evidence the sounds have been occurring for much longer: Abu Dabbab means “the Father of Knock” in Arabic, hinting at a tectonic mystery at least as ancient as the name of the long-inhabited coastal region. Now, scientists are offering a novel explanation for the uniquely noisy seismic events, and their discovery is revealing new information about the underlying structure of the Red Sea region.

A terribly low voice for a new terror bird

Fri, 17 Jul 2015 09:31:09 -0400

A nearly complete skeleton of Llallawavis scagliai is on display at the Lorenzo Scaglia Municipal Museum of Natural Sciences in Buenos Aires, Argentina. Credit: M. Taglioretti and F. Scaglia.

A recently discovered fossil skeleton is giving paleontologists a nearly complete look at a new species in the family of big-beaked giants known as “terror birds.” Thought to have grown as tall as 3 meters, these flightless birds roamed South America as apex predators before going extinct about 2.5 million years ago.

Ice (Re) Cap: June 2015

Mon, 01 Jun 2015 10:18:21 -0400

Researchers deploy a hydrophone in Icy Bay, Alaska, to monitor noise levels in the glacial fjord. Credit: Jeffrey Nystuen.

From Antarctica to the Arctic; from polar caps, permafrost and glaciers to ocean-rafted sea ice; and from burly bears to cold-loving microbes, fascinating science is found in every nook and crevasse of Earth’s cryosphere, and new findings are announced often. Here are a few of the latest updates.

Of temperature and tone: Has climate shaped human languages?

Fri, 03 Apr 2015 13:16:43 -0400

The global distribution of tonal (blue dots) versus nontonal (orange dots) modern languages as identified in a new study. Credit: K. Cantner, AGI, after Everett et al., PNAS, 2015.

Humans today speak more than 6,500 languages, and thousands more dialects once spoken have gone extinct. Understanding how and why so many languages have evolved over human history has long been the work of linguists. Recently, however, the emerging field of geo-phonetics has begun looking into how geography — and perhaps climate — affects language. In a new study, researchers suggest that humidity and temperature, which can impact our ability to craft certain sounds, appear to have influenced the evolution of tonality in languages in different parts of the world.

Earth tides in A major

Thu, 05 Jan 2012 06:41:58 -0500

Earth experiences small, millimeter-sized tides, called Earth tides. Using a dataset from NASA’s Jet Propulsion Laboratory in California from A.D. 1600 to A.D. 2200, Engebretson calculated the net gravitational force of the sun and the moon at particular intervals and then mapped them onto the A major scale.

Musical magnetic reversals

Thu, 05 Jan 2012 06:41:58 -0500

Although Earth’s magnetic field currently points toward the North Pole, the planet’s magnetic dipole flips direction every few hundred thousand years or so. Engebretson tracked the last 85 million years of these magnetic reversals, with higher pitches representing shorter polarities (a period of time when the direction of the magnetic field stays the same), and lower pitches longer ones.

Of sounds and cetaceans: Quieting a noisy underwater world

Thu, 05 Jan 2012 06:41:58 -0500

Marine mammals live in a world of sound. In the open ocean, whales and dolphins depend on sound waves, using echolocation to navigate, find food, attract mates and communicate. But their clicks and calls are not the only noises underwater: Oil and gas exploration, seafloor mapping, and ship and submarine navigation have increased dramatically over the past few decades, making the world’s oceans noisier than ever.

Putting Earth's history to sound

Thu, 05 Jan 2012 06:41:58 -0500

Geologist Dave Engebretson of Western Washington University in Bellingham has made an amateur career out of turning scientific data into sound. George Muspot

Geophysicist Dave Engebretson of Western Washington University in Bellingham has struggled with his eyesight since birth. But when his vision took a serious downturn in 1996 — today he has difficulty recognizing faces up close — Engebretson grasped for the world of sound. He has made a considerable hobby out of audifying scientific data — taking numbers from datasets and setting them to sound frequencies to create seconds-long clips at his home studio. The result ranges from a series of differently pitched explosions that fast-forward through the last 20,000 years of eruptions along the Cascade Mountains, to haphazard movements up and down the music scale that represent changes in the tides.