Stratigraphy and Radiocarbon Dating of Pyroclastic Deposits at Merapi Volcano

Stratigraphy and Radiocarbon Dating of Pyroclastic Deposits at Merapi Volcano

Stratigraphy and radiocarbon dating of pyroclastic deposits at Merapi Volcano, Central Java, reveals ,10,000 years of explosive eruptions. Highlights include: (1) Construction of an Old Merapi stratovolcano to the height of the present cone or slightly higher. Our oldest age for an explosive eruption is 9630 ± 6014 C y B.P.; construction of Old Merapi certainly began earlier. (2) Collapse(s) of Old Merapi that left a somma rim high on its eastern slope and sent one or more debris avalanche(s) down its southern and western flanks. Impoundment of Kali Progo to form an early Lake Borobudur at ~3400 14C y B.P. hints at a possible early collapse of Merapi. The latest somma-forming collapse occurred ~1900 14C y B.P. The current cone, New Merapi, began to grow soon thereafter. (3) Several large and many small Buddhist and Hindu temples were constructed in Central Java between 732 and ~900 A.D. (roughly, 1400–1000 c y B.P.). Explosive Merapi eruptions occurred before, during and after temple construction....
Read More
Merapi, History and Future Changes

Merapi, History and Future Changes

A Working Paper Merapi, History and Future Changes - Merapi Volcano, in the central part of Java, is regarded as the most active and most dangerous volcano in Indonesia. Merapi is a young stratovolcano with a total volume estimated between about 100 and 150 km3, according to the importance given to the Pre-Merapi (Berthommier, 1990). A strong uncertainty remains concerning the beginning of its activity. Information on Merapi eruptive activity is scattered. A concise and well-documented summary of this activity has been long needed to assist researchers and hazard-mitigation efforts. The present effusion rate is about 105 m3/month (Siswowidjoyo et al., 1995); if we assume a constant rate since the beginning, Mount Merapi could be between 8300 and 125 000 years old. On the basis of field studies and geochronological data, its history is divided into four Periods: Ancient, Middle, Recent and Modern Merapi. The Ancient Period may have begun around 40 000 y BP and lasted until 14 000 y...
Read More