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Magnitude 7.7 Earthquake – 68 km NNW of Ende, Indonesia

earthquake.usgs.gov

224 points by Bender · 63 comments

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while_true_

Interesting this earthquake struck shortly after a solar eclipse, implying significant spring tide forces were present. The earthquake occurred near dawn, when the sun/moon pair, Indonesia, and the Earth's core formed a right angle to each other, creating tidal tension forces on the crust.

Tidal forces have been linked to the Dec. 26, 2004 Sumatra earthquake. This paper claims there's a significant link between tidal forces and earthquakes in the region (https://doi.org/10.1029/2006GL027074). The authors conclude "The observed relationships suggest that the cyclical crustal flexing, which will be at a maximum at full or new moons, might provide sufficient extra force to a plate-boundary region already on the point of rupture to trigger an earthquake that was ‘waiting to happen’."

insaider

Is this big enough to produce a Tsunami? Apparently maybe only a small localised one, but I'm supposed to be getting the ferry from Lombok to Bali shortly and two of those have already burnt down the last 2 weeks!

  • decimalenough

    A ferry in the open ocean is one of the safer places to be during a tsunami. Remember, it's not a surf-style wave, but a gradual increase in water level.

    • kylecazar

      There's an eerie video that went around of a ship hitting the 2011 tsunami in Japan at open sea. It demonstrates the idea pretty well.

      https://youtube.com/shorts/igfP5CQAkHU?is=TJqk4lxxhYkK8hQV

    • aziaziazi

      After the tsunami, would the current induced by the water drawback disrupt the ferry ability to come back ? I wonder if the ocean “rise” again (water on top of water) or if it’s more a current-style (water push water) movement.

      • monster_truck

        Extremely. They are quite slow laterally (a couple knots while docking), the lateral currents (which are not constant or unidirectional) reach 2-4x+, throwing them into whatever happens to be in the way.

        AFAIK the bigger issue is that the boats are grounded so violently when the water recedes that the hulls get destroyed before they even have a chance.

        This tends to be why they put everything they have into getting further out to sea the moment a warning is issued.

    • throwaway894345

      boarding the ferry may not be the most pleasant, however.

  • Polizeiposaune

    Indonesia's tsunami bulletins appear to be here:

    https://rtsp.bmkg.go.id/publicbull.php

    They've declared the event over - some waves were generated but nothing particularly large. Bulletin 3 for the recent quake includes wave height observations - maximum reported was 94cm; most were under 50cm.

  • Grimburger

    Tsunamis are only an issue close to shore. In the ocean it's barely a mild wave.

    In a boat going further out is the safest thing you can do if there's a tsunami warning.

  • wiml

    I've seen "possible tsunami" pre-warnings, and a sea level gauge at/near Lembar showing sea level oscillations - so I would recommend keeping a close watch on some information source that's better than HN comment threads, yes.

    • lostlogin

      Correct, but also, I’d bet there is a lurking tsunami expert here somewhere. Nothing is ever too niche for HN.

      • Melatonic

        There's a tsunami warning list you can sign up for. As well as global earthquake alerts. In my experience they arrive very quickly

        Usually earthquakes on land don't trigger tsunamis but are more damaging locally

  • bdickason

    I would upgrade the ferry and make sure to get a high quality one given all the swell in the ocean already (most of bali had 6ft+ waves yesterday) and this incident. Not worth the risk.

  • seanmcdirmid

    Lombok will have lots of higher ground at least. You really just have to be careful on and near the beach.

  • yxhuvud

    Easily big enough, but how deep it was generated and how the movements happened do impact the risk a lot.

  • pestatije

    the tsunami risk is negligible compared to the fire risk

  • reilly3000

    Safe travels, friend.

  • rootsudo

    Interesting times for the ferry indeed

CookieCrisp

I know large earthquakes are effectively random (ignoring aftershocks) but this feels like a lot this year, yeah?

  • HaloZero

    Yeah, I looked this up and USGS literally has a page about this.

    https://www.usgs.gov/faqs/why-are-we-having-so-many-or-so-fe...

    According to long-term records (since about 1900), we expect about 16 major earthquakes in any given year. That includes 15 earthquakes in the magnitude 7 range and one earthquake magnitude 8.0 or greater. In the past 40-50 years, our records show that we have exceeded the long-term average number of major earthquakes about a dozen times.

    You can see a map of ALL the 7+ here:

    https://earthquake.usgs.gov/earthquakes/map/?extent=-89.0318...

    The search filtering is a bit hard to find in the UI but the parameters in the URL can be modified. (We had 16+ 7.0 last year as a comparison)

    • astrobe_

      I've always wondered if the melting of glaciers would move masses from one place to another and induce some tectonic moves. But the mass is most likely not significant enough; water/ice has a relatively low density after all.

      • dev1ycan

        It's more likely related to planetary positions and or solar cycle/activity, "recent studies suggest a notable statistical correlation between specific solar magnetic milestones and the shifting phases of the El Niño-Southern Oscillation"

        Like in theory it doesn't make sense that el niño causes earthquakes, yet there seems to be more prominent ones during el niño however if both are related to sun cycle/activity it would make more sense (seeing how the moon affects earth as well)

        • smolder

          The deep earth isn't all that well studied, so while we know a fair amount about plate tectonics, there could be hidden factors influencing that action in ways we can't anticipate from recorded history. Who's to say there aren't 1000 or 10k year cycles of earthquakes? Something novel could happen too, but our records don't let us set probabilities for 10k year natural disasters the way we can with 100 year tropical storms, floods, or earthquakes.

          • defrost

            > Who's to say there aren't 1000 or 10k year cycles of earthquakes?

            The Stratigraphy department of the International Union of Geological Sciences would be the obvious first port of call.

            Follow that up with an off book chat with digital archivists for commercial oil and gas exploration geologists.

            • smolder

              Does the stratigraphy department of the international union of geological sciences have such thorough knowledge that they can make predictions about this stuff on geologic timescales? Getting any kind of truth from commercial oil companies is expensive. To them, knowledge is a weapon, and they lie whenever it is advantageous to lie.

          • Melatonic

            Or influence by the moon just as it pulls on oceans. Lot of liquid magma down there.

            Or maybe some once in a rare incident involving coronal mass ejections somehow affecting the core of the planet. Could even be a delayed effect.

            • fragmede

              One of the More out there theories is that some earthquakes are caused by high energy cosmic particles going through the Earth.

  • teacpde

    Yea, feel like a lot of big ones this year, but looking it up https://en.wikipedia.org/wiki/List_of_earthquakes_in_2026 it is actually not necessarily worse than previous years.

    • marcosdumay

      Given we are barely beyond half of the year, that puts us close to the outlier that was 2023 in the 7+ range.

      2023 also had a strong el-niño event.

  • ortusdux

    76 quakes ranking 7.0+ so far this decade, including 10 this year.

    https://en.wikipedia.org/wiki/List_of_earthquakes_2021%E2%80...

  • beloch

    Earthquakes can occur in swarms[1] (distinct from aftershocks), with many of a similar size (i.e. Not a big quake followed by smaller ones) occurring in a small area over "relatively short" periods of time (i.e. days, weeks, or years).

    The USGS map shows the 7.7 quake being followed by about 19 other smaller quakes near or in Indonesia within just a few hours. These are probably aftershocks.

    -------

    [1]https://en.wikipedia.org/wiki/Earthquake_swarm

  • keeda

    Sure feels like it in my corner of the Bay Area, since we had a prolonged earthquake swarm earlier this year, even hitting a record number of earthquakes per day or something like that.

  • kermatt
    • LeBit

      > Note: While it may look like there have been an increase in total number of earthquakes since about 2020, this is actually due to the increasing number of seismic stations installed in the park since 2020 that are able to detect smaller (<= 0.5 magnitude) earthquakes. If you look at the number of earthquakes >= 1.0, the rate has remained about the same.

      • jwilber

        Somehow I don’t think people are confusing raw seismic station earthquake counts with the three back-to-back high profile/magnitude earthquakes that recently occurred in Venezuela, Colombia, and Indonesia.

        I understand the point, maybe those recent earthquakes aren’t ood, but still.

        • Melatonic

          There are also likely a lot of earthquakes we don't notice because they don't effect populated areas. There's a lot of ocean around the ring of fire.

    • goda90

      Why does this page say there have been 0 >2.5mag earthquakes this year?

      • teraflop

        Because this particular sensor network is only monitoring earthquakes in the Pacific Northwest of the USA, not worldwide.

  • onion2k

    Randomness without clusters probably isn't random.

  • jtfrench

    It does feel like a lot

  • jeffrwells

    HN highlighting a lot this year, is all

embedding-shape

Interestingly enough, south of Spain also had a earthquake this morning: https://www.nytimes.com/interactive/2026/08/14/world/europe/..., last one was in 2025 but before that 2021. Maybe too few data points to extrapolate any wider pattern, but skimming https://en.wikipedia.org/wiki/List_of_earthquakes_in_Spain they seem to be picking up in frequency.

alekstret

This morning, when I woke up, I checked the phone notifications. I saw some alerts from the LastQuake app that a major earthquake occurred on Flores. I didn't feel it here in Bukit, Bali, where I currently reside.

burnt-resistor

So Google Earth says the ocean depth at the epicenter is 6,286 ft / 1,916 m, but I couldn't find a corresponding tsunami alert or evaluation of risk.

  • mikeyouse

    Looks like it was a strike-slip fault, so a much lower tsunami risk compared to a subduction / dip-slip fault.

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