Finally, he went to the California Institute of Technology (Caltech, United States) where he earned a PhD in Geology in 1998,[4][5][6] with a thesis focussing on neotectonics and earthquake studies.

With grants, he pioneered and developed a continuous network of SuGAr GPS stations since 2002 to monitor tectonic movements in Sumatra in collaboration with Caltech USA and the Earth Observatory of Singapore.

He became the head of the national team for the preparation of Guidelines for Natural Disaster Risk Analysis (PARBA) organized by UNDP and BNPB in 2008–2009.

[9][10][11][12] In 2011, he took a leading part in the controversial geological survey of the archeological site at Gunung Padang as chief geologist of the government-sponsored Tim Terpadu Riset Mandiri (TTRM, 'Integrated and Independent Research Team').

[15] In October 2023, an article by Natawidjaja et al., published in Archaeological Prospection, claimed that Gunung Padang is the oldest pyramid in the world, dating as far back as 27,000 years ago.