Recently, absorption and scattering at depths 800-1000 m in South Pole ice have been studied with transit-time distributions of pulses from a variable-frequency laser sent between emitters and receivers embedded in the ice. At 800-1000 m, scattering is independent of wavelength and the scattering centers are air bubbles of size ? wavelength. At 1500-2000 m it is predicted that all bubbles will ...

Abstract. The variations of δO2/N2 and δAr/N2 in the Dome Fuji ice core were measured from 112 m (bubbly ice) to 2001 (clathrate hydrate ice). Our method, combined with low storage temperature samples (−50 ∘C), successfully excludes post-coring gas-loss fractionation signals our data. From bubbly middle bubble–clathrate transition zone (BCTZ) (112–800 m) below BCTZ (>1200 m), data exhibit or...

Abstract. The variations of ?O2/N2 and ?Ar/N2 in the Dome Fuji ice core were measured from 112 m (bubbly ice) to 2001 (clathrate hydrate ice). Our method, combined with low storage temperature samples (?50 ?C), successfully excludes post-coring gas-loss fractionation signals our data. From bubbly middle bubble–clathrate transition zone (BCTZ) (112–800 m) below BCTZ (>1200 m), data exhibit or...

Ocean Drilling Program and Deep Sea Drilling Project downhole data from three areas, the southwestern Japan Nankai margin, the continental slope off Peru, and the Blake-Bahama Outer Ridge, provide temperature calibrations for bottom simulating reflectors (BSR) that mark the base of a clathrate hydrate stability field. The inferred temperatures at BSRs provide an important reference for the mapp...

Gas hydrates are systems of prime importance. In particular, hydrogen hydrates are potential materials of icy satellites and comets, and may be used for hydrogen storage. We explore the H₂O-H₂ system at pressures in the range 0-100 GPa with ab initio variable-composition evolutionary simulations. According to our calculation and previous experiments, the H₂O-H₂ system undergoes a series of tran...