{"id":5750,"date":"2026-03-19T22:54:43","date_gmt":"2026-03-19T14:54:43","guid":{"rendered":"https:\/\/heybali.info\/news\/?p=5750"},"modified":"2026-03-19T22:54:46","modified_gmt":"2026-03-19T14:54:46","slug":"indonesias-megathrust-risk-draws-japans-attention-what-it-means-for-bali","status":"publish","type":"post","link":"https:\/\/heybali.info\/news\/indonesias-megathrust-risk-draws-japans-attention-what-it-means-for-bali\/","title":{"rendered":"Indonesia\u2019s Megathrust Risk Draws Japan\u2019s Attention. What It Means for Bali"},"content":{"rendered":"\n

New hazard map shows increased seismic risk, with Bali located along a high-risk subduction segment<\/em><\/p>\n\n\n\n

BADUNG, Bali<\/strong> \u2014 Indonesia\u2019s updated 2024 Earthquake Source and Hazard Map has identified 14 megathrust zones across the archipelago, highlighting a higher level of seismic risk than previously understood and drawing attention from international researchers, including scientists from Japan.<\/p>\n\n\n\n

The revised map, released by Indonesian authorities, shows denser hazard contours in several regions compared to the 2017 version\u2014an indication of stronger potential ground shaking and accumulated tectonic stress.<\/p>\n\n\n\n

Among those closely examining the findings is Kosuke Heki, a professor at Hokkaido University, who says Indonesia\u2019s geological characteristics closely resemble Japan\u2019s Nankai Trough\u2014one of the most active megathrust regions in the world.<\/p>\n\n\n\n

Parallels With Japan\u2019s Seismic History<\/strong><\/h3>\n\n\n\n

Speaking during his time as a visiting researcher at Badan Riset dan Inovasi Nasional, Heki pointed to similarities in how tectonic stress builds along subduction zones in both countries.<\/p>\n\n\n\n

\u201cWe understand that magnitude 8 earthquakes in Japan occur at intervals of approximately 50 to 100 years. This was our classical view before major earthquakes occurred,\u201d he said.<\/p>\n\n\n\n

While predicting the exact timing of earthquakes remains beyond current science, Heki stressed that long-term monitoring of crustal deformation is essential for risk mitigation.<\/p>\n\n\n\n

He highlighted the importance of Global Navigation Satellite Systems (GNSS) and seafloor geodesy in detecting how stress accumulates beneath the Earth\u2019s surface.<\/p>\n\n\n\n

\u201cWe see seismic coupling locking almost along the entire trench axis. Even at shallow plate boundaries, strain continues to accumulate for the next earthquake,\u201d he explained..<\/p>\n\n\n

\n
\"Photo:
Photo: A segment of the megathrust zone in southern Java and Sumatra. (Doc. Journal “On the potential for megathrust earthquakes and tsunamis off the southern coast of West Java and southeast Sumatra, Indonesia”)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Role of Slow Slip Events<\/strong><\/h3>\n\n\n\n

Heki also pointed to \u201cslow slip events\u201d\u2014gradual tectonic movements that often occur before major earthquakes.<\/p>\n\n\n\n

Although these movements are barely perceptible, they may provide early signals of changing stress conditions beneath the surface.<\/p>\n\n\n\n

\u201cThese phenomena have been observed repeatedly in the Nankai Trough and other regions of Japan. One such event could potentially trigger the next major earthquake,\u201d he said.<\/p>\n\n\n\n

For Indonesia, developing the ability to detect these signals could significantly improve early warning and disaster preparedness.<\/p>\n\n\n\n

A Country of Active Subduction Zones<\/strong><\/h3>\n\n\n\n

Indonesia sits along a vast chain of active subduction zones stretching from Sumatra through Java, Bali, Lombok, and into eastern regions such as Maluku.<\/p>\n\n\n\n

Heki noted that this geological setting gives Indonesia a strong opportunity to build monitoring systems comparable to those in Japan.<\/p>\n\n\n\n

\u201cCurrently, I am working on this issue in Indonesia,\u201d he said, pointing to ongoing scientific collaboration between the two countries.<\/p>\n\n\n\n

What the New Map Reveals<\/strong><\/h3>\n\n\n\n

The updated hazard map underscores the scale of seismic energy stored beneath Indonesian waters.<\/p>\n\n\n\n

The Aceh-Andaman megathrust shows the highest potential, with an estimated maximum magnitude of 9.2. The Java megathrust, running along the island\u2019s southern coast and extending eastward, carries a potential magnitude of 9.1.<\/p>\n\n\n\n

Other significant zones include Mentawai-Siberut, Mentawai-Pagai, and Enggano, each with the potential to generate earthquakes approaching magnitude 9.<\/p>\n\n\n\n

\"Photo:
Photo: A segment of the megathrust zone in southern Java and Sumatra. (Doc. Journal “On the potential for megathrust earthquakes and tsunamis off the southern coast of West Java and southeast Sumatra, Indonesia”)<\/figcaption><\/figure>\n\n\n\n

Seismic Gaps Raise Long-Term Concerns<\/strong><\/h3>\n\n\n\n

Indonesia\u2019s Badan Meteorologi Klimatologi dan Geofisika has also highlighted two megathrust segments\u2014Sunda Strait and Mentawai-Siberut\u2014as being in a \u201cseismic gap\u201d condition.<\/p>\n\n\n\n

These areas have not released significant energy for centuries, with the last major earthquakes recorded in 1757 and 1797.<\/p>\n\n\n\n

The agency cautioned that this does not mean an earthquake is imminent.<\/p>\n\n\n\n

\u201cWhat this means is that energy continues to accumulate because no major earthquake has occurred for a long time. It does not indicate that an earthquake will happen in the near future,\u201d BMKG said in an official statement.<\/p>\n\n\n\n

What It Means for Bali<\/strong><\/h3>\n\n\n\n

For Bali, the findings reinforce its position along an active tectonic boundary within the broader Java\u2013Bali\u2013Nusa Tenggara subduction system.<\/p>\n\n\n\n

While most earthquakes felt on the island are small to moderate, the surrounding megathrust system is capable of generating much larger events.<\/p>\n\n\n\n

For residents, investors, and millions of visitors each year, the message is not one of alarm\u2014but of awareness.<\/p>\n\n\n\n

Indonesia shares the same seismic reality as countries like Japan and Chile: earthquakes cannot be predicted with precision, but their risks can be better understood and managed.<\/p>\n\n\n\n

With stronger monitoring systems and continued scientific collaboration, experts say the focus remains on preparedness\u2014ensuring that when a major event occurs, its impact can be minimized.<\/p>\n\n\n\n

#heybalinews<\/a><\/strong><\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

New hazard map shows increased seismic risk, with Bali located along a high-risk subduction segment BADUNG, Bali \u2014 Indonesia\u2019s updated 2024 Earthquake Source and Hazard Map has identified 14 megathrust zones across the archipelago, highlighting a higher level of seismic risk than previously understood and drawing attention from international researchers, including scientists from Japan. The […]<\/p>\n","protected":false},"author":3,"featured_media":5751,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"content-type":"","jnews-multi-image_gallery":[],"jnews_single_post":{"format":"standard"},"jnews_primary_category":[],"jnews_override_bookmark_settings":[],"jnews_food_recipe":[],"enable_food_recipe":"","food_recipe_title":"","food_recipe_description":"","food_recipe_serve":"","food_recipe_time":"","food_recipe_prep":"","food_recipe_level":"","food_recipe_keywords":"","food_recipe_category":"","food_recipe_cuisine":"","food_recipe_yield":"","food_recipe_calories":"","enable_print_recipe":"","ingredient":[],"instruction":"","jnews_social_meta":[],"jnews_review":[],"enable_review":"","type":"","name":"","summary":"","brand":"","sku":"","good":[],"bad":[],"score_override":"","override_value":"","rating":[],"price":[],"jnews_override_counter":[],"jnews_post_split":[],"footnotes":""},"categories":[53,51],"tags":[47,106,146,82,77,834,371,514,54,55],"class_list":["post-5750","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-weather-natural-events","category-bali-update","tag-bali","tag-bali-expat","tag-bali-life","tag-bali-tourism","tag-indonesia","tag-megathrust","tag-natural-disasters","tag-natural-events","tag-news","tag-weather"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/posts\/5750","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/comments?post=5750"}],"version-history":[{"count":0,"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/posts\/5750\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/media\/5751"}],"wp:attachment":[{"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/media?parent=5750"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/categories?post=5750"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/heybali.info\/news\/wp-json\/wp\/v2\/tags?post=5750"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}