EARTH

February 2018

www.earthmagazine.org

MEDITERRANEAN DEPOSITS FROM STORMS, NOT TSUNAMIS

BEAVERS PRESERVE WETLANDS DURING DROUGHTS

EXPLORING THE ROCKS AROUND LAS VEGAS

HOW WILDFIRES SHAPED EARTH

THROUGH TIME

EARTHFEATURES

34

24

38

ON THE COVER: Researchers are unraveling the complicated history of fire on Earth, and using new techniques to gather data on wildfires and predict their behavior and the weather they can create. Credit: iStockPhoto.com/CoisaX

February 2018 | vol. 63 no. 2 | www.earthmagazine.org

VOICES

64 GEOLOGIC COLUMN: TRAVELS WITH CLAUDIA: REDISCOVERING AMERICA

A husband and wife set out to rediscover some places they knew well in their youth, and some they had only read about in books. Along the way, they learned much about where this country has been, where it is, and where it’s going. | Fred Schwab

24 | A FLAMMABLE PLANET: Fire Finds Its Place in Earth History

For hundreds of millions of years, wildfires have shaped the planet, from the plants, animals and ecosystems around us to the air we breathe. Yet scientists are only beginning to understand the planet’s fiery past. | Kate S. Zalzal

34 | DIVIDING LINE: The Past, Present and Future of the 100th Meridian

In 1878, John Wesley Powell first advanced the idea that the climatic boundary between the United States’ humid East and arid West lay along the 100th meridian, which runs from pole to pole and, today, cuts through six U.S. states. But what does it really mean, and what is its future? | Harvey Leifert

38 | TRAVELS IN GEOLOGY: Las Vegas: The Scenery Beyond the Slots

Beyond the Strip lie southern Nevada’s craggy limestone peaks, colorful sandstone canyons, and enormous conservation areas that, despite the searing desert heat, harbor a tremendous diversity of plants and wildlife. From soaring summits and graceful bighorn sheep to prehistoric petroglyphs, this desert oasis has a lot to offer the geo-minded traveler. | Terri Cook and Lon Abbott

ON THE WEB AT www.earthmagazine.org

NEWS

12 LOOKING UNDER LUSI: INDONESIAN MUD VOLCANO LINKED TO NEARBY VOLCANIC COMPLEX

13 SMALL WARM PONDS: IDEAL INCUBATORS FOR FIRST LIFE?

14 MEDITERRANEAN TSUNAMI RECORD MAY BE OVERREPORTED

15 DENALI’S ASIAN DINOSAURS

16 ARIZONA ROAD HAZARD HAS SURPRISING SOURCE

17 UNEXPECTED NANOPARTICLES TRACE COAL POLLUTION

18 ISOTOPES SUGGEST ANCIENT TURQUOISE MINE WAS PROLIFIC

19 BEAVERS PRESERVE WETLANDS IN WATER-STRESSED AREAS

20 CONGRESS MULLS OPTIONS FOR ABANDONED MINES LEGISLATION

21 ICE AGE DIDN’T FREEZE FLORIDA’S CATEGORY 5 HURRICANES

22 FOSSIL REEFS SHOW SEA LEVEL ROSE IN BURSTS

22 FOSSIL SEA TURTLE HATCHLING REVEALS ITS EOCENE PROTEINS

23 RED PLANET ROUNDUP

14

17

20

22

DEPARTMENTS

4 FROM THE EDITOR

6 PERSPECTIVES

46 MINERAL RESOURCE OF THE MONTH: Titanium

48 GEOMEDIA: BOOKS: Putting “Seeds on Ice” to Protect Crop Diversity

49 CONGLOMERATE: A Geo Word Jumble

50 WHERE ON EARTH?

52 DOWN TO EARTH: With Fire Meteorologist Craig Clements

55 BENCHMARKS: FEBRUARY 12, 1986: France and the U.K. Sign the Treaty of Canterbury, Paving the Way for the Chunnel

60 CLASSIFIEDS: Career Opportunities