Major revisions are required to the manuscript, in order to consider it for publication. In addition to the comments by the referees, I suggest the Authors to refer to internationally recognized classification on sinkholes, such as that proposed in Gutierrez et al. (2008, 2014) rather than referencing to single publications. This well help the reader to have a better understanding of the processes Authors are describing.
Further, Authors do not take into any account a number of papers dealing exactly with the topic of the manuscript, that is the relations between sinkhole and seismicity. I kindly invite the Authors to consider such references when preparing the revised version of the manuscript. Below Authors will find a list of suggested references:
DelPrete,S.,Iovine,G.,Parise,M.,Santo,A.,2010b.Origin and distribution of different types of sinkholes in the plain areas of Southern Italy. Geodin. Acta 23, 113–127.
Gutiérrez, F., Guerrero, J., Lucha, P., 2008. A genetic classification of sinkholes illustrated from evaporite paleokarst exposures in Spain. Environ. Geol. 53, 993–1006.
Gutierrez F., Parise M., De Waele J. & Jourde H., 2014, A review on natural and human-induced geohazards and impacts in karst. Earth Science Reviews, vol. 138, p. 61-88, doi: 10.1016/j.earscirev.2014.08.002.
Iovine G. & Parise M., 2008, I sinkholes in Calabria. In: Nisio S. (a cura di) I fenomeni naturali di sinkhole nelle aree di pianura italiane. Memorie Descrittive della Carta Geologica d’Italia, vol. 85, p. 335-386.
Kawashima, K., Aydan, O., Aoki, T., Kishimoto, I., Konagal, K., Matsui, T., Sakuta, J., Takahashi, N., Teodori, S.-P., Yashima, A., 2010. Reconnaissance investigation on the damage of the 2009 L'Aquila, Central Italy earthquake. J. Earthq. Eng. 14, 817–841.
Parise, M., Perrone, A., Violante, C., Stewart, J.P., Simonelli, A., Guzzetti, F., 2010. Activity of the Italian National Research Council in the aftermath of the 6 April 2009 Abruzzo earthquake: the Sinizzo Lake case study. Proc. 2nd Int. Workshop “Sinkholes in the Natural and Anthropogenic Environment”, Rome, pp. 623–641.
Santo, A., Del Prete, S., Di Crescenzo, G., Rotella, M., 2007. Karst processes and slope instability: some investigations in the carbonate Apennine of Campania (southern Italy). In: Parise, M., Gunn, J. (Eds.), Natural and Anthropogenic Hazards in Karst Areas: Recognition, Analysis, and Mitigation. Geological Society, London. 279, pp. 59–72.

Minor revisions are requsted to the manuscript. In the attached file you will find some comments, corrections, and requests of clarification. I am looking forward to receiving the revised manuscript