Geoglyphs are large designs typically longer than about 13 feet (4 m) and produced on the ground by arranging rocks or soil. They are distinctive elements of the archaeological record along the Pacific coast of the Americas, from California to Chile. The Nazca lines of Peru are famous geoglyphs of animals and geometric shapes, constructed in the arid deserts of south-central coastal Peru between about 500 BCE and 500 CE.
Popocatépetl, in southern Mexico, is North America’s 2nd-highest volcano. This volcano has been erupting for millennia—and the recent activity beginning in late May 2023 is bringing additional concern about the possibility of a significant eruption. The tectonic setting of this volcano has some interesting and unusual characteristics.
Bright blue ponds looming out of the red desert landscape near Moab, Utah, recently prompted my interest in the potash harvested from the pools. The potassium-bearing contents of the ponds will become a key ingredient of synthetic fertilizers. These are essential to feed the growing population on our planet, but fertilizer components are not in infinite supply, plus are causing many environmental problems.
The global need for lithium-ion batteries is projected to grow by over 500% in the next decade, creating a soaring demand for new battery factories and key components of batteries, especially metals. Establishing sustainable battery-supply chains is an important goal. Fortunately, metals are infinitely reusable, and so billions of dollars are being poured into new battery recycling plants.
Around 13,000 years ago, Paleoindian hunters were making red ochre from iron-rich hematite collected from a quarry in the western foothills of the Rocky Mountains. Red ochre had an important role in Paleoindian societies, and is associated with many campsites, kill sites, graves, caches—and notably, found in rock art. Worldwide, the historical record of red ochre mines extends back tens of thousands of years.
The Great Pacific Garbage Patch comprises three massive, floating marine debris “islands” within a circular ocean current, or gyre - stark reminders of the major environmental pollutant that plastic has become. Fortunately, scientists and engineers are developing novel alternatives for tasks currently filled by petrochemicals. Two alternative packaging materials that especially intrigue me are the mycelium of fungus like mushrooms and spider silk.
The risk of megafloods is increasing dramatically as global temperatures rise and store more moisture in the atmosphere. We are not as prepared as many assume. For California, both history and modeling studies of the storm events we can expect in the future provide interesting insights.
The Star of Bethlehem, or the Christmas Star, has an important place in tradition. A mystery surrounds the history of this star, and searches for an explanation have concerned theologians, philosophers, and scientists for nearly 2,000 years. In this post, I focus on whether astronomers have identified a celestial body that could have been a Christmas star.
Erupting volcanoes are forming new real estate all around our planet. Beneath Iceland and Hawaii, hot lava upwelling from deep underground is hardening into rock. Hotspots create chains of volcanoes on these islands as a tectonic plate slowly crosses a mantle plume. In Iceland, there are also volcanic eruptions occurring from the location astride the spreading center known as the Mid-Atlantic Ridge. The result: LOTS of lava.
Rich deposits of metals cover vast areas of deep ocean floors. Mining companies have focused on polymetallic nodules, and large-scale seafloor mining could begin by 2024. Given the potential for irreversible consequences to ocean environments and our climate, many are calling for a moratorium or a delay in this mining.