Wednesday, November 30, 2011

Nias Landslide, Wednesday, November 30, 2011

Seven people were killed and 30 others were missing after heavy rain triggered a landslide on the Indonesian island of Nias on Wednesday, 30 November 2011. The landslide slammed into a village in Majo Kampung Barije district on the island in North Sumatra province. At least 37 houses were buried under the mud, seven people were confirmed dead and thirty other people were missing.

It is known that the prominent factors of landslide in Indonesia are lithology and morphology. Highly weathered material can be easily found in Indonesia. If it occurred on the steep morphology and water penetrate into the material, it will weaken the slope and increase the potential of mass movement as it cross the threshold. Heavy rains were recorded over the past three days prior to the landslide.

Evacuation still in progress, although it has been limited by the weather condition.

Monday, October 3, 2011

Indonesian government raises alert on Anak Krakatau volcano in Sunda Strait, West Java

The Indonesian Volcanology Center has raised the alert from level II to Level III on Anak Krakatau Mt in Sunda Srait since last Sunday of September 30, 2011 following a number of volcanic quakes and increase of solfatara zone in the mountain flank. As for info, the Center has set four levels increasing intensity of volcanic activity with level I for the lowest and level IV for the highest.

Anak Krakatau Mt is one of the most active volcanoes in Indonesia, located within the area of the older Krakatau complex now represent as Panjang, Sertang and Rakata islands. Geographically, it’s located at the position of -6.100615,105.422688. The closest cities are Lampung, Jakarta and Banten. One hundred eruptions were recorded since June 11, 1927 with recurrence intervals every 1-6 years. Since 2007, eruptions phase occur every year in this mountain. Unfortunately, seismograph and several GPS station in Anak Krakatau were buried by eruption material lately, resulting lack of observation since July 10, 2011. On September 18, 2011 the seismograph back to its normal operation and the center observe rising in activity including the occurrence of volcanic swarm with intensity of 1-4 events per minutes.

For the last four years, strombolian eruption predominate the eruption type of this volcano. The explosive eruption disperses materials in bomb, blocks, lapilli and ash size that spread in a radius of 500-1500 around the volcano.

The Center said that at the moment it was not necessary to evacuate residents on the coast line area near the Sunda Strait but asked the residents as well as tourists to keep away from the mountain. The Anak Krakatau crater area and the area within 2km from the volcano is closed to any activity.

Hot-line Information: Geological Hazard andVolcanology center of Indonesia (Pusat Vulkanologi dan Mitigasi Bencana Geologi) phone number: +62-22-7272606 and Krakatau Observatory Center: +62-254-651449.

Location map of the Anak Krakatau Mt.

Upper Figure caption: Anak Krakatau Mt. (image source: Kompas)

Monday, September 5, 2011

M 6.7 North Sumatra Earthquake, Tuesday, September 6, 2011

Magnitude 6.7 struck North Sumatra region on Tuesday, September 06, 2011 at 00:55 AM local time. The epicenter located 59 km northeast of Singkilbaru-Aceh, 75 km southeast of Kutacane-Aceh, 78 km southwest of Kabanjahe-North Sumatra, 100 km southwest of Medan, onshore at position 2.81°S, 97.85°E with a depth of 78 km.

As in Tuesday September 6, 2011, 3.15 AM, no fatalities reported yet. Power is out throughout the epicenter region. Even though the authorities ensure that no tsunami is going to occurs, panicked residents still fled to higher ground fearing giant waves.

Update: As in September 9, 2011, at least two fatalities were reported and numbers of building collapses.

Figure: BMKG (Indonesian climatology and geophysics agency) shake map of this earthquake (Source)

Resident inspecting the damaged house caused by the earthquake (image source)

Sunday, August 28, 2011

Lokon’s Mountain, North Sulawesi erupts again, August 28, 2011

The eruption of Mount Lokon has not abated. On Sunday, August 28, 2011 at 07.51 local time, another eruption occurred again following last month eruption. According to The Volcanic and Geological Disaster Mitigation Center (PVMBG) of Indonesia, the eruptions column reached 2,500 meters from Topaluan crater of the mountain. Series of volcanic tremors were recorded since 8pm on Saturday. With an extensive increasing numbers of earthquakes occurs about six hours prior to the eruption, 69 volcanic tremors were recorded during span time of 00.00-06.00 that day. Previously, after the July 14 eruption, the agency has lowered this mount's alert level from level IV to level III.

Images source: Detik

Friday, August 12, 2011

Indonesian government raises alert on Papandayan Mt, West Java

On Saturday, August 13, 2011 at 4am, local time, the Indonesian Volcanology Center has raised the alert from level II to Level III on Papandayan Mountain in West Java. The Center has set four levels increasing intensity of volcanic activity with level I for the lowest and level IV for the highest (alert level code chart).

The 2665 m (8,743 ft) Papandayan mountain is a complex stratovolcano with four large summit craters, the youngest of which was breached to the NE by collapse during a brief eruption in 1772 and contains active fumarole fields. Geographically, it’s located at the position of 7.32°S / 107.73°E. The closest major cities are Garut and Bandung. It began spewing gas on its three crater of Welirang, Manuk and Baladagama along with intense volcanic tremor and increase of rate of deformation for the last few days.

After its first historical eruption in 1772, in which collapse of the NE flank and produced a catastrophic debris avalanche that destroyed 40 villages and killed nearly 3000 persons, only small phreatic eruptions had occurred (1923, 1942) prior to an explosive eruption that began in November 2002.

Figure caption: Papandayan eruption in 2002 (source).

Tuesday, August 9, 2011

Important publication on earthquake forecasting developed by the International Commission on Earthquake Forecasting (ICEF)

An important report of the International Commission on Earthquake Forecasting (ICEF) entitled "Operational Earthquake Forecasting: State of Knowledge and Guidelines for Implementation", was recently published in Annals of Geophysics (vol. 54, num. 4, pp. 315-391, 2011; doi: 10.4401/ag-5350). Hopefully the report will be useful to other counties developing operational forecasting procedures and protocols, including Indonesia. The complete report can be freely downloaded from: this website.


State of Knowledge and Guidelines for Utilization

Authors: Thomas H. Jordan, Yun-Tai Chen, Paolo Gasparini, Raul Madariaga, Ian Main, Warner Marzocchi, Gerassimos Papadopoulos, Gennady Sobolev, Koshun Yamaoka, Jochen Zschau

Following the 2009 L'Aquila earthquake, the Dipartimento della Protezione Civile Italiana (DPC), appointed an International Commission on Earthquake Forecasting for Civil Protection (ICEF) to report on the current state of knowledge of short-term prediction and forecasting of tectonic earthquakes and indicate guidelines for utilization of possible forerunners of large earthquakes to drive civil protection actions, including the use of probabilistic seismic hazard analysis in the wake of a large earthquake. The ICEF reviewed research on earthquake prediction and forecasting, drawing from developments in seismically active regions worldwide. A prediction is defined as a deterministic statement that a future earthquake will or will not occur in a particular geographic region, time window, and magnitude range, whereas a forecast gives a probability (greater than zero but less than one) that such an event will occur. Earthquake predictability, the degree to which the future occurrence of earthquakes can be determined from the observable behavior of earthquake systems, is poorly understood. This lack of understanding is reflected in the inability to reliably predict large earthquakes in seismically active regions on short time scales. Most proposed prediction methods rely on the concept of a diagnostic precursor; i.e., some kind of signal observable before earthquakes that indicates with high probability the location, time, and magnitude of an impending event. Precursor methods reviewed here include changes in strain rates, seismic wave speeds, and electrical conductivity; variations of radon concentrations in groundwater, soil, and air; fluctuations in groundwater levels; electromagnetic variations near and above Earth's surface; thermal anomalies; anomalous animal behavior; and seismicity patterns. The search for diagnostic precursors has not yet produced a successful short-term prediction scheme. Therefore, this report focuses on operational earthquake forecasting as the principle means for gathering and disseminating authoritative information about time-dependent seismic hazards to help communities prepare for potentially destructive earthquakes. On short time scales of days and weeks, earthquake sequences show clustering in space and time, as indicated by the aftershocks triggered by large events. Statistical descriptions of clustering explain many features observed in seismicity catalogs, and they can be used to construct forecasts that indicate how earthquake probabilities change over the short term. Properly applied, short-term forecasts have operational utility; for example, in anticipating aftershocks that follow large earthquakes. Although the value of long-term forecasts for ensuring seismic safety is clear, the interpretation of short-term forecasts is problematic, because earthquake probabilities may vary over orders of magnitude but typically remain low in an absolute sense (< 1% per day). Translating such low-probability forecasts into effective decision-making is a difficult challenge. Reports on the current utilization operational forecasting in earthquake risk management were compiled for six countries with high seismic risk: China, Greece, Italy, Japan, Russia, United States. Long-term models are currently the most important forecasting tools for civil protection against earthquake damage, because they guide earthquake safety provisions of building codes, performance-based seismic design, and other risk-reducing engineering practices, such as retrofitting to correct design flaws in older buildings. Short-term forecasting of aftershocks is practiced by several countries among those surveyed, but operational earthquake forecasting has not been fully implemented (i.e., regularly updated and on a national scale) in any of them. Based on the experience accumulated in seismically active regions, the ICEF has provided to DPC a set of recommendations on the utilization of operational forecasting in Italy, which may also be useful in other countries. The public should be provided with open sources of information about the short-term probabilities of future earthquakes that are authoritative, scientific, consistent, and timely. Advisories should be based on operationally qualified, regularly updated seismicity forecasting systems that have been rigorously reviewed and updated by experts in the creation, delivery, and utility of earthquake information. The quality of all operational models should be evaluated for reliability and skill by retrospective testing, and they should be under continuous prospective testing against established long-term forecasts and alternative time-dependent models. Alert procedures should be standardized to facilitate decisions at different levels of government and among the public. Earthquake probability thresholds should be established to guide alert levels based on objective analysis of costs and benefits, as well as the less tangible aspects of value-of-information, such as gains in psychological preparedness and resilience. The principles of effective public communication established by social science research should be applied to the delivery of seismic hazard information.

Full text: PDF

Tuesday, July 19, 2011

Arizona State University initiative to help geologically active Indonesia

By: Nikki Staab

Arizona State University’s School of Earth and Space Exploration has teamed up with the Indonesian-based Bakrie Group to develop an international initiative called the Bakrie Initiative in Geological Hazards to support and promote research in Indonesia on the core geologic topics of volcanoes, earthquakes and hydrothermal systems.

The goal of the initiative is to advance research, teaching and outreach aimed at helping mitigate the potentially disastrous effects of Indonesia’s geologically dangerous landscape, while deepening the global scientific community’s understanding of earthquakes, volcanic eruptions and hydrothermal systems. This joint philanthropic partnership will provide leadership and serve as a focal point for Indonesian earth science research. One of the broader aims of the Bakrie Initiative is to cultivate strong partnerships with Indonesian universities, institutions and communities, as well as with international organizations conducting related research.

Indonesia is no stranger to the devastating effects of tsunamis, earthquakes, and volcanic eruptions. As more and more people live, work, play and travel in volcanically and tectonically active regions, the risks to life, property, infrastructure and global commerce are constantly escalating.

“Indonesia, as a densely-populated emerging nation with a high-concentration of geologic hazards, is an ideal location for testing scientific theories and protocols aimed at ensuring the successful co-evolution of modern societies with an active and sometimes dangerous natural world,” says Amanda Clarke, volcanology professor in the School of Earth and Space Exploration in ASU’s College of Liberal Arts and Sciences. “Our school’s unique approach to discovery and knowledge melds the creative strengths of both science and engineering, which uniquely positions us to advance understanding of geologic hazards and the environment from a multidisciplinary perspective.”

SESE’s educational and research programs are designed explicitly to emphasize the importance of technology in scientific exploration. This multidisciplinary approach is particularly important in the struggle to reduce global risk from geologic hazards in an increasingly densely populated world and positions SESE perfectly to advance and deepen understanding of geologic hazards and the environment from both a scientific and engineering perspective.

Special emphasis will be placed on hazards and the interaction between a dynamic Earth and modern cities. Although largely conducted in Indonesia and Southeast Asia, this research will increase fundamental understanding of geologic systems that ultimately may be important to many nations around the globe.

“As a university designed for the express purpose of solving problems of global significance, ASU is well-equipped to carry out projects like this,” said ASU President Michael M. Crow. “Substantial investments from private sector partners like the Bakrie group are instrumental to making socially beneficial research initiatives possible. We are optimistic that the work facilitated by the Bakrie Group’s generosity will have far-reaching, positive impacts on the quality of life on people around the world.”

Christopher Fong, senior vice president of international affairs at The Bakrie Group, commented: “The ASU Bakrie Initiative is part of our commitment to engendering a deeper understanding of Indonesia’s unique, and highly volatile, geology,” he said. “This critical research will drive the development of technologies to assist scientists more accurately monitor and predict geological hazards in the future.

“The partnership with Arizona State University’s School of Earth and Space Exploration, one of the world’s leading geological research institutes, will provide significant opportunities to promising Indonesian scientists, and cultivate stronger ties with Indonesian universities. We congratulate Gadjah Mada University’s Gayatri Marliyani, recipient of the first Bakrie PhD fellowship.”

Marliyani, the first Bakrie Fellow, comes from one of Indonesia’s most impoverished regions, Gunungkidul. As a child, she was fascinated with the topography of her region’s mountainous areas, especially the majestic Merapi Volcano. But it was the Yogyakarta earthquake of 2006, which she personally experienced that caused her to want to study and understand earthquakes and active faults.

The Bakrie Initiative will be launched by three initial projects for which the ASU teams have already conducted preliminary research and planning. The results of these projects should significantly improve understanding and provide quantification of regional shallow earthquake hazards and improve the scientific community’s understanding of the relationship between tectonic seismic activity, volcanic eruptions, and hydrothermal systems, which could have positive impact on hazards mitigation efforts.

“I am pleased and excited to be selected as the recipient of the Bakrie fellowship through the Bakrie Initiative in Geological Hazard at ASU,” says Marliyani. “By conducting this type of research in Indonesia, I believe it will create great and long-lasting benefits for people living not only in Indonesia, but in geologically dangerous settings all over the world.”

News Link:
ASU News.
SESE News.

School of Earth and Space Exploration, ASU

Thursday, July 14, 2011

Thursday, July 14 2011, Mount Lokon-North Sulawesi Eruption

Mount Lokon in Indonesia's North Sulawesi province erupted on Thursday, July 14, 2011, 23.45 local time (eastern Indonesian time) spewing sand and ash that reached 1.500 meter in height, blanketed two villages on its slope, Kinilouw and Kakaskase. The ashes reach as far as Tondano Lake. Lava cascaded from the mouth of the crater, triggering forest fires along its western slope. Approximately 11.000 villager lives within radius of 3.5 km from the volcano forced to leave their homes into evacuation shelters outside the forbidden zone. (Upper Photo: AFP)

Two hours later on Friday, July 15, 2011 at 01.05, smaller eruption occurs with eruption column reaches 600 meters in height. That eruption was followed by third eruption at 1:10am on Friday.

The 1689-meter high Mount Lokon began its activity few weeks ago, indicated by increasing of volcanic tremors. Its last major eruption in 1991 killed a Swiss hiker and forced thousands of people to flee their homes. The authority has raised the alert level of this volcano to its highest on Sunday, July 10, 2011.

The evacuation is still in progress, the exact number of causalities and refugees are not yet released. The only victim so far was a 56-year-old woman who died of a heart attack.

Image: Mount Lokon, North Sulawesi eruption on Thursday, 14 July 2011 (image source: Kompas)

Mount Lokon precursor eruption on July 10, 2011 (image courtesy of: Henric Hansson)

Location of Mount Lokon in North Sulawesi, Indonesia

Update: As in 7/19/2011, at least 5.205 people have evacuated the region, but evacuations may continue as Mount Lokon's activity was still intense.

The National Disaster Management Agency (BNPB) recorded two additional eruptions on Monday (7/18/2011) that were only 10 minutes apart. The first one was registered at 1:24 p.m. local time, and the second at 1:34 p.m. The first eruption produced a thick gray cloud that rose to a height of 200 meters (656 feet), while the second one spewed out a 600-meter (1,968-feet) ash cloud above the active crater.