Submarine deposition of volcaniclastic material from the 1995-2005 eruptions of Soufriere Hills volcano, Montserrat

Soufrière Hills volcano, Montserrat, has been erupting since 1995. During the current eruption, a large part of the material produced by the volcano has been transported into the sea, modifying the morphology of the submarine flanks of the volcano. We present a unique set of swath bathymetric data collected offshore from Montserrat in 1999, 2002 and 2005. From 1999 to 2002, pyroclastic flows associated with numerous dome collapses entered the sea to produce 100 Mm3 deposit. From 2002 to 2005, the 290 Mm3 submarine deposit is mainly from the 12–13 July 2003 collapse. These data allow us to estimate that, by May 2005, at least 482 Mm3 of material had been deposited on the sea floor since 1995. We compare on-land characteristics and volumes of dome collapse events with the submarine deposits and propose a new analysis of their emplacement on the submarine flanks of the volcano. The deposition mechanism shows a slope dependence, with the maximum thickness of deposit before the break in the slope, probably because of the type of the dense granular flow involved. We conclude that from 1995 to 2005 more than 75% of the erupted volume entered the sea.

York Township (Mich.) residences and business, ca. 1874

Left to right: Res. of Geo. F. Richards, Sec. 16, York Tp. Mich.; Res. of Selden Orr, Sec. 16, York Tp. Mich.; Res. of John Coe, Sec. 3, York Tp. Mich.; Res. of E. Pearson, Sec. 11, York Tp. Mich.; Res. of Geo. Coe, Sec. 8, York Tp. Mich.; Milan House, Lyman Burnham, Proprietor, Milan, York Tp. Mich. Publication information: Chicago, Ill. : Everts & Stewart, 1874.

Top: Res. of Asa M. Darling, Sec. 12, Augusta Tp. Mich. Bottom: Res. of C.C. Harmon, Sec 18, Augusta Tp. Mich.

Augusta Township (Mich.) residences. Insets: Built 1849. Hop House. Publication information: Chicago, Ill. : Everts & Stewart, 1874.

President's house and yard

On verso: Views on the campus at the U. of M. Ann Arbor Mich. [Photo ... by Black & Co.]

President's House

On verso: Photographed in 1887 by A.L. Colton of '89

Prof's House, North University, West Residence

Originally West Professor's house on North University. Became Homeopathic Hospital. Wing added in rear of building in 1879. School of Dentistry 1875-1877. Psychological Lab 1903-1914. Building razed in 1914. On verso: Rear view, taken from campus side, looking across North University, where on the left-hand side ... Octagonal House, long owned by Alexander Winchell ... now site of Hill Auditorium ... taken before rear wing added to make it into the Homepathic Hospital.