For decades, sand has been used to simulate the effects volcanic ash may have on aircraft, but in a new study covered by EARTH Magazine, scientists used samples of real volcanic ash from volcanoes of different eruptive styles from around the world.

This issue, EARTH Magazine explores the world's top weather-related killer: exposure to extreme heat. Humans' response to extreme heat leads to heat stress, an illness related to the body's inability to cool itself. Humidity plays a crucial role, because as humidity increases, the ability of sweat to evaporate and cool the body decreases.

A magnitude-7.1 earthquake struck Chile on Jan. 2, 2011, or so scientists thought. Now, with increasing sensor sensitivity and advances in the quantitative analysis of earthquakes, scientists have revealed that this quake was actually a doublet. This meant that instead of just one massive quake, two similarly large earthquakes struck very near to one another within seconds. The closely spaced doublet was missed by global monitoring networks during the initial aftermath of the quake, and, as EARTH Magazine explores, it presents a major challenge to earthquake and tsunami warning systems. Experts agree this is a challenge that must be brought to the forefront of seismic research.

For years historians and scientists have tried to understand the ancient marvel of the Roman aqueducts to better understand Rome itself. Now archaeologists are using a new method - the buildup of travertine within the Anio Novus aqueduct - to determine how much water flowed into Rome.

In a Utah cave, paleontologists are exploring the fossil record preserved in owl pellets since the Pleistocene glaciation. The fossils in the pellets are giving the scientists a glimpse of how the ecosystems have changed over time both from natural variation and more recent changes brought on by human settlement.

Water demand in communities nationwide is decreasing due to better efficiency and more effective conservation programs, but also due to demographic shifts that may require a rethink in the way that water usage is modeled.

Humans depend on copper for everything from electrical wiring to water pipes. To meet demand, the metal has been largely mined from Porphyry Copper Deposits (PCDs). For decades, scientists generally agreed upon the geological processes behind PCD formation; now EARTH Magazine examines two new studies that suggest alternatives to these long-held understandings.

From the tiny microcosms of atomic theory and futuristic colonies on Mars to dinosaurs walking the Earth, science illustrators translate scientific findings and theories into something lifelike, accurate and aesthetically pleasing. The July cover story from EARTH Magazine, "Science Illustrators: Making the Invisible Visible," takes readers on a behind-the-scenes of how illustrators transform a scientific concept into an informed work of art.

In the years following the 1986 Chernobyl nuclear disaster, forest fires billowed plumes of contaminated smoke, carrying radioactive particles throughout Europe on the wind. Now, researchers fear that a shift to a hotter, drier climate in Eastern Europe could increase the frequency of these fires.

With hundreds of seismic, infrasound, hydroacoustic and radionuclide-detecting stations operating continuously around the world, CTBTO scientists - and, increasingly, researchers outside the organization - are realizing the potential of all the data collected. CTBTO data have been used to understand major natural events such as the 2013 Chelyabinsk meteor and the 2011 Japanese earthquake, tsunami and eventual nuclear disaster. And in the future, it may contribute to improved volcano monitoring and understanding of atmospheric processes.