This post is from my notes for the first week of lecture in Wheels of Metals: Urban Mining for a Circular Economy on Coursera, and it highlights—for common metals (iron, copper, aluminum)—useful properties that makes the metal attractive for applications, what applications the metal is used in, where and how the metal is mined, how the metal is processed, and how it is recycled. Read more
Life cycles of common metals
Cortney Education, Science & Technology, Society & Culture + coursera, metals, recycling
Leave a reply
October 2014 blood moon & jack-o'-lantern sun
Cortney Science & Technology + blood moon, lunar eclipse, orbits, sun
Not to be outdone by the October blood moon, the sun put on its best Halloween face and imitated a jack-o'-lantern on October 8. The brighter regions—its eyes and mouth, so to speak—appear as such due to magnetic fields in the corona (the sun's atmosphere) that cause the release of more energy. Read more →
Mount Sinabung, Indonesia October 2014 eruptions
Cortney Science & Technology + indonesia, pyroclastic flows, tectonics, volcanoes
Mount Sinabung—a 2,460-meter-high Indonesian stratovolcano which has erupted in 2010, 2013, and early 2014—kicked off October with ongoing magnificent eruptions, extruding viscous intermediate lava lobes which collapsed, sending break-neck speed pyroclastic flows as far as 3.5-4 km. Compare this Pelean eruption to last month's devastating phreatic eruption in Japan, another island arc. Read more →
Updated map of ocean floor doubles resolution, reveals volcanoes, spreading centers
Cortney Science & Technology + geology, oceanography
Using satellite radar altimetry (which measures elevation) combined with previous data, researchers at UC San Diego have doubled the resolution of the previous decades-old ocean floor map. Large ocean features create a small "bump" in the sea surface above them; for example, a mile high volcano elevates the ocean surface by 10 centimeters. Read more →
Mount Ontake: phreatic eruption in September 2014 kills 30+ hikers
Cortney EMS, Health & Medicine, Science & Technology + japan, volcanoes
Mount Ontake—Mount Fuji's lesser known cousin, a 3,000 meter tall stratovolcano in central Japan—erupted at noon on September 27, giving just 12 minutes of notice in the form of tremors. Read more →
Five fossils important for understanding tetrapod evolution
Cortney Science & Technology + biology, evolution, fish, paleontology, paleozoic
Tetrapods are four-limbed vertebrates that evolved from lobe-finned fish during the Devonian (395 million years ago), invading the land and ultimately leading to today's the amphibians, reptiles, birds, and mammals.
Read more →
Amniotes of the Late Paleozoic & Mesozoic
Cortney Science & Technology + biology, evolution, mesozoic, paleontology, paleozoic
Amniotes are tetrapods (four-limbed vertebrates) whose eggs contain amnions, an adaption that keeps them from drying out on land; they first appeared during the Carboniferous. There are two main groups, synapsids and sauropsids (anapsids, diapsids, and euryapsids), which differ in their evolutionary history and their skull morphologies (specifically, the types of fenestrae or "holes" in the skull). For a much more detailed look at the evolution and taxonomy of aminotes, check out Palaeofiles from the University of Bristol.
Volcano news: how slopes affect lava flows, challenge to traditional volcano model, Mauna Loa waking up
Cortney Science & Technology + geology, hawaii, lava flows, rift zones, volcanoes, yellowstone
The summer of 2014 has been an exciting one for volcano science!
Easy Science: The Great Oxygenation Event
Cortney Science & Technology + ancient earth, archean, atmosphere, Easy Science, geology, precambrian, volcanoes
The Earth wasn't always a friendly place to live. Not only was it covered in lava and constantly eruption, its atmosphere was chocked with volcanic gases like carbon dioxide and sulfur dioxide. How and when did the atmosphere reach its current oxygen-rich state? This post will walk through the processes as well as some of the evidence that allows us to understand what happened. While I describe as a series of apparently discrete steps, it's important to remember that these processes sometimes overlapped and that they occurred over a span of time, often millions or billions of years.
How zircons help us date and understand the ancient earth
Cortney Science & Technology + ancient earth, geology, zircons
Small and unimposing at just fractions of a millimeter across, the igneous silicate mineral zircon (ZrSiO4) lays its claim to fame as the oldest earth material at 4.4 billion years old. The secret to zircon's success is its durability and tenacity. When other minerals break apart or turn into other minerals, zircon bravely trudges on. My former professor, Dr. Alex Glass of Duke University, described zircon as "the thing that never leaves," comparing zircon to a person who awkwardly remains at a house party long after all the other guests have left. He suggested that rather than diamonds, zircons should be the ultimate symbol of everlasting love. Read more →