Crystal chemistry suggests magma changes quickly before a huge eruption.

Chemical reactions deep inside the Earth fuel magma’s gem-laden upward journey. (p. 11)

Biologists document surprising differences among deep-sea animals at hydrothermal vent fields. (p. 5)

A fossilized feathered dinosaur dined on bird not long before its own demise. (p. 13)

On October 4, the National Snow and Ice Data Center posted information on its website indicating that the summer melt of sea ice in the Arctic, this year, approached — but did not quite match — the record set four years ago. A team of European scientists now concludes NSIDC underestimated those Arctic losses.

Photosynthesis appears to be somewhat speedier than conventional wisdom had suggested, a new study finds. If true, this suggests computer projections are at risk of overestimating the potential for trees to sop up carbon dioxide, a major greenhouse gas.