Saturday, September 26, 2015

Super Blood Moon

The confluence of three celestial phenomena happen tomorrow evening:
The last supermoon eclipse occurred in 1982.

Celestial phenomena are predictable because we have studied and understand planetary movements in the solar system.
Nothing comes close to the precision with which physics enables you to understand the world around you. It's the laws of physics that allow us to say exactly what time the sun is going to rise. What time the eclipse is going to begin. What time the eclipse is going to end.
Neil deGrasse Tyson

Blood Moon
source: Anne Dirkse
Full moon

Tomorrow's full moon will be both a harvest moon and a blood moon.

A harvest moon is the full moon that falls closest to the fall equinox, which was last Wednesday.

A blood moons describes the red-tinted moon observed during a lunar eclipse. During a lunar eclipse, sunlight directed around the edges of the Earth refracts through Earth's atmosphere filtering out all but red, giving the moon its blood red tint.


Tomorrow's full moon will be a supermoon, or the full moon in perigee.

The moon orbits Earth in an elliptical path meaning that the distance between Earth and moon varies over an orbital cycle, giving us supermoons and micromoons.

A supermoon compared to a micromoon
source: Friends of NASA

Supermoons occur when the moon's orbital path transports it to the closest point to Earth. Micromoons occur when the moon is at its farthest point from Earth. A supermoon is about 31,000 miles closer to the Earth than a micromoon.
The closer proximity of a supermoon makes it appear 14% larger and 30% brighter.
The stronger gravitational pull of the supermoon causes wider variation in high and low tide levels.

Lunar Eclipse

Tomorrow's full moon will undergo a total eclipse.

Tomorrow night, the Earth will line up between the sun and the moon. The moon will gradually move into the shadow of the earth until it falls into darkness (i.e, a total eclipse).
Lunar eclipse
source: Luca

Under clear skies, tomorrow's lunar eclipse should be visible from longitudes stretching from the eastern Pacific to western Asia, including the Americans, Europe, and Africa.
Three things cannot be long hidden: the sun, the moon, and the truth.
Gautama Buddha
The next supermoon eclipse occurs in 2033.


Saturday, September 19, 2015

Continental Volcano Chain

Geologists posit that hotspots, expressed on the ground surface as observable volcanic features, are fed by underlying super-heated plumes of mantle materials (shown in red).

The large-scale motion of Earth's lithosphere (shown in yellow) is known as plate tectonics.

Mantle hotspots remain stationary compared to the dynamic shifting of Earth's plates. As the lithosphere moves laterally, chains of volcanic islands in the ocean, or chains of continental volcanoes, form over millions of years.

A noted continental chain was created by the Snake River Plain-Yellowstone hotspot. The Snake River Plain-Yellowstone hotspot is the source of a 400 mile chain of volcanic features created over 15 million years. It extends from what is today the Idaho-Oregon border up intoYellowstone National Park in northwest Wyoming.

The Lava Creek eruption, the most recent significant volcanic event in the chain, occurred some 640,000 years ago causing the Lava Creek Tuff and the Yellowstone Caldera.

The longest continental chain, three times as long as the track caused by the Yellowstone hotspot, has recently been identified in Australia by a team of geologists.

Cosgrove Volcano Track

Geologists have recently identified the longest series of continental volcanoes, named the Cosgrove volcano track. The track spans 1,243 miles across eastern Australia (shown below). Geologists posit that as Australia moved north over a hotspot, volcanic features were created over the course of 33 million years.

Cosgrove volcano track

"We realized that the same hotspot had caused volcanoes in the Whitsundays and the central Victoria region, and also some rare features in New South Wales, roughly halfway between them."
― Dr. Rhodri Davies, Australian National University
Hotspots occur where rocks melt to create flowing magma. Heated by the hot core, fluid rock in the mantle rises and falls. Plumes of magma occasionally penetrate the crust to produce volcanoes. Over millions of years, continental plates move laterally over the hotspots thus creating a travel log expressed by volcanic features marking the surface of the Earth.
"Ultimately this new understanding may help us to reconstruct the past movements of continents from other hotspots."
― Dr. Nick Rawlinson, University of Aberdeen


Saturday, September 12, 2015

Know thy Tribe

H O M O.   Nosce te ipsum
Carl Linnaeus published Systema Naturae in 1735. Linnaeus described humans (Homo) with the latin phrase nosce te ipsum which translates to know thyself.

Systema Naturae lists more than 10,000 species of plants and animals and introduced Linnaean taxonomy.

Linnaean taxonomy became the foundation for biological nomenclature and provides the hierarchical basis for how we classify animals, plants, bacteria and other organisms including ourselves, homo sapiens.

Human classification gets revised as we unearth more bones and fossils.
You are truly home only when you find your tribe.
Srividya Srinivasan
Like others animals, the classification of homo sapiens is illustrated by a taxonomic chain that starts in the broad classification of the animal kingdom then gets increasingly specific before arriving at our genus and species homo sapiens.

Human Classification
Kingdom Animalia
Phylum Chordata (animals with a notochord; in fish, reptiles, birds and mammals, the notochord becomes the vertebral column)
Class Mammalia
Order Primates (lemurs, bush babies, tarsiers, monkeys, apes and humans)
Family Hominidae (orangutans, gorillas, chimpanzees and humans)
Subfamily Homininae (gorillas, chimpanzees and humans)
Tribe Hominini (humans and our close extinct relatives)
Genus Homo
Species Sapiens

Homo naledi
Berger et al. 2015 
A new hominin species found in a cave in South Africa was announced last Thursday (Berger et al). The new species is named Homo naledi. Naledi means star in the local Sesotho language.
Naledi refers to the Rising Star Cave where the bones were discovered undisturbed on an earthen flow below a narrow crack in a limestone wall.

Naledi is a new member of our hominini tribe.

The collection of bones in a remote cave chamber suggests that early hominins intentionally placed their dead which is a behavior previously thought to be limited humans.
Tribe follows tribe, and nation follows nation, like the waves of the sea. It is the order of nature, and regret is useless.
Duwamish Chief Seattle, 1854 Oration


Saturday, September 5, 2015

Core Energy

Using a three-dimensional supercomputer simulation that aggregated seismic wave pathways generated from 273 earthquakes over the past 20 years, geophysicists from Lawrence Berkeley National Laboratory recently mapped plumes of heat energy from Earth's interior:

Heat plumes at boundary between the Earth's
metal core and it's rocky mantle 1,800 miles
below ground.
Lawrence Berkeley National Laboratory
University of California, Berkeley

This visualization of the plumes of hot rock rising through the mantle correlate to hotspots around the planet where we observe the ongoing generation of chains of volcanic islands.

Geologists have long recognized the ongoing occurrences of terrestrial changes as Sir Archibald Geikie observed in his 1879 lecture to the Royal Geographical Society:
Looking back across the long cycles of change through which the land has been shaped into its present form, let us realise that these geographical revolutions are not events wholly of the dim past, but that they are still in progress. So slow and measured has been their march, that even from the earliest times of human history they seem hardly to have advanced at all. But none the less are they surely and steadily transpiring around us. In the fall of rain and the flow of rivers, in the bubble of springs and the silence of frost, in the quiet creep of glaciers and the tumultuous rush of ocean waves, in the tremor of the earthquake and the outburst of the volcano, we may recognise the same play of terrestrial forces by which the framework of the continents has been step by step evolved.
Sir Archibald Geikie, lecture at the RGS, 24 March 1879
Structural Cutaway
source: kelvinsong

Earth's crust consists of oceans and continents.

Underlying the crust is the mantle which is about 1,800 miles thick.

The mantle consists of hot but solid rock. Below the mantle is the outer core which is a liquid layer of molten iron and nickel.

And many a fire there burns beneath the ground.

The inner core is solid iron.

Terrestrial Change

Heated by the hot core, rock in the mantle rises and falls. Plumes of hot rock occasionally penetrate the crust to produce volcanoes. As Earth's crust moves laterally around the planet via plate tectonics, the hot stationary rock in the mantle penetrate the crust to generate chains of islands.

The Galapagos, Cape Verde, Samoa, Hawaiian, and Canary islands are examples of volcanic island chains created by Earth's crust moving laterally over stationary super-heated mantle rock.