INICIO>ÁREAS DE CONOCIMIENTO>Geología

Dra. Alessandra Pensa  
Posdoctorante

Email: alepensa@geociencias.unam.mx
Teléfono: (+52) (55) 5623-4104 Ext. 159, (442) 238-1104 Ext. 159
Extensión UNAM: 34104 Ext. 159

Research Interests

Volcanology, Explosive eruptions, Stratigraphy, Geochemical stratigraphy, Field Mapping, Paleomagnetism, Charcoal Reflectance analysis, Emplacement temperature and transport processes of ignimbrites
CURRENT FIELD AND INVESTIGATION
My research focuses on the reconstruction of emplacement temperatures of explosive volcanic products by using thermal remanent magnetization (TRM) of lithic clasts, Reflectance analysis (Ro %) and Raman spectroscopy of charcoaled wood fragments. During my PhD I had the chance to study the emplacement temperatures of three ignimbrites emplaced during the last main Plinian eruption (4.6 ka) of Fogo Volcano, Sao Miguel, Azores Archipelago. My postdoc project aims to use different proxies as TRM, Ro% and Raman spectroscopy for the temperature evaluation of the 10 km long block ad ash flow (body)and the co-ignimbritic ash cloud emplaced in July 2015 in Colima Volcano. Furthermore the same approach will be applied for the reconstruction of the temperature of the fall-out deposit emplaced during the 1913 Plinian eruption of Colima volcano. The comparison of three independent proxies aims to defining a more precise method for the estimation of emplacement temperature and to improving the accuracy of TRM analysis applied to fall-out deposits. 

Recent Publications

1) Pensa A., Cas R.A.F., Giordano G., Porreca M. and Wallenstein N.(2015)
“Transition from steady to unsteady Plinian eruption column: the VEI 5,4.6 ka Fogo A Plinian eruption, São Miguel, Azores” Journal of Volcanology and Geothermal Research 305 (2015) 1–18
2) Pensa A., Giordano G., Cas R.A.F., Porreca M. and Corrado S. (2015)
“Thermal state and implications for eruptive styles of the intraplinian and climactic ignimbrites of the 4.6 ka Fogo A eruption sequence, São Miguel, Azores”. Bulletin of Volcanology Vol.77(11), pp.1-19
3) Pensa A., Porreca M., Corrado S., Giordano G. and Cas R.A.F. (2015)
“Calibrating the pTRM and charcoal reflectance (Ro %) methods to determine the emplacement temperature of ignimbrites: Fogo A sequence, São Miguel, Azores, Portugal, as a case study. Bulletin of Volcanology, 2015, Vol.77(3), pp.1-19
4) Barberi F., Carapezza M., Giordano G., Pensa A., Ranaldi M., (2008)
“The aquifer in the gravel base of the Tiber, a geothermal resource for the city of Rome”. Descriptive memories of the Geological Map of Italy

Conferences
35TH IGC Cape Town(oral presentation)
“Map of submerged volcanic structures in Italy”

Il Pianeta Dinamico 2015 Florence (oral presentation)
“The geochemical evolution of the Fogo A eruptive sequence: timing of development of anti-rapakivi textures and implications for dual magma source or zoned magma chamber models”

IUGG Conference 2015 Prague (oral presentation)
“Calibrating the pTRM and charcoal reflectance (Ro %) methods to determine the emplacement temperature of ignimbrites: Fogo A sequence, São Miguel, Azores, Portugal, as a case study”

IAVCEI Conference 2013, Japan (poster presentation)
“The thermal state of pyroclastic flow deposits of the 4.5 ka Fogo A plinian eruption sequence, São Miguel, Azores, using TRM analysis and charcoal reflectance data, and implications for eruption and flow processes.”

Caldera collapse Conference 2012, Bolsena, Italy. (poster presentation)
“The Complex, 4.6ka Fogo A Caldera Forming Plinian Eruption, São Miguel, Azores Islands, and Relevance to Understanding the Eruption Style and Transportation Processes.”