01732nas a2200217   4500008004100000022001400041245010000055210006900155300001400224490000800238520108300246653001801329653002201347653002401369100001601393700001501409700001301424700001401437700002001451856004301471       2012                        eng d  a2156-220200aA detailed view into the eruption clouds of Santiaguito volcano, Guatemala, using Doppler radar0 adetailed view into the eruption clouds of Santiaguito volcano Gu  an/a–n/a0 v1173 aUsing Doppler radar technology we are able to show that eruptions at Santiaguito volcano, Guatemala, are comprised of multiple explosive degassing pulses occurring at a frequency of 0.2 to 0.3 Hz. The Doppler radar system was installed about 2.7 km away from the active dome on the top of Santa Maria volcano. During four days of continuous measurement 157 eruptive events were recorded. The Doppler radar data reveals a vertical uplift of the dome surface of about 50 cm immediately prior to a first degassing pulse. Particle velocities range from 10 to 15 m/s (in the line of sight of the radar). In 80% of the observed eruptions a second degassing pulse emanates from the dome with significantly higher particle velocities (20–25 m/s again line of sight) and increased echo power, which implies an increase in mass flux. We carry out numerical experiments of ballistic particle transport and calculate corresponding synthetic radar signals. These calculations show that the observations are consistent with a pulsed release of material from the dome of Santiaguito volcano.10aDoppler radar10aeruption dynamics10aSantiaguito volcano1 aScharff, L.1 aZiemen, F.1 aHort, M.1 aGerst, A.1 aJohnson, J., B.  uhttp://dx.doi.org/10.1029/2011JB008542