Prologue

On 28th Septembre 2012, For the first time I go to a volcano. It is Krakatau volcano which is recorded has massif eruption on 26th and 27th August 1883. That massif eruption remained three main islands (Panjang, Rakata and Sertung island). Since 1927, new island rose in the middle of those islands See figure 1.

Figure 1. Maps of Krakatau in 2008

My team and I went there with to conduct GPS survey for monitoring volcano activities because it erupts on 2nd Septembre 2012. We actually have seven GPS stations, one in each  surrounding islands and four in Anak Krakatau but two of them are gone because of previously eruption.So, what we do is only conducting survey on the remainning GPS stations.