The NanTroSEIZE Project: Drilling through a plate boundary in an active subduction zone.

Guest post by David Middleton

From Real Clear Science:

These 7 Expeditions Could Reveal Some of Earth’s Biggest Secrets in 2019

By Adam Mann

This past year brought tons of fascinating new information about our planet. But as scientists gaze into their crystal balls, they can see that this year is also sure to contain exciting surprises. Here we take a look at the seven most highly anticipated geophysics and Earth science expeditions, missions and meetings of 2019.

Inspecting Thwaites Glacier for cracks


Creating amazing new ice maps


Drilling into the cause of an earthquake
Off the southwest coast of Japan, deep below the Pacific Ocean, sits the Nankai Trough, an active subduction zone where one plate of the Earth’s crust is slipping beneath another. It is one of the most seismically active places on the planet, responsible for the 8.1-magnitude Tōnankai earthquake that rocked Japan in 1944. This year, the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) began drilling into the fault. It is the “first [expedition] to drill, sample and instrument the earthquake-causing, or seismogenic portion of Earth’s crust, where violent, large-scale earthquakes have occurred repeatedly throughout history,” according to the mission’s website. Rocks collected next year will be analyzed to see how slippery or solid they are, allowing researchers to “understand more about the conditions that might lead to an earthquake on these type of fault,” wrote team member John Bedford of the University of Liverpool on the expedition’s blog.

Measuring the forest and the trees


Exploring a buried Antarctic lake


Learning the history of coral reefs


Exploring the deep biosphere


Real Clear Science

Does anyone really care about cracks in the Thwaites Glacier or new ice maps?  And pictures of trees taken from the ISS?  Didn’t Landsat already do this sort of thing?  Coral reefs are cool… But we already know their history,  Maybe the history we know isn’t alarmist enough.  Drilling into a subglacial lake is cool… unless they find The Thing.

Deep biosphere… Who cares?  If you’ve seen one biosphere, you’ve seen them all.  And, the deep biosphere is only a small piece of Deep Carbon 2019… Which is more of a convention than it is an expedition.

Now “drilling into the cause of an earthquake”… That’s really cool… Unless it triggers an earthquake.  Technically the plan is to drill through the plate boundary in the Nankai Trough subduction zone.  A fault system associated with massive earthquakes and tsunamis.

Nankai Trough Seismogenic Zone Experiment drilling expeditions have reached the final phase this October. About 11 years have passed since the first IODP (International Ocean Discovery Program) operation by D/V Chikyu cruise in September 2007. So far D/V Chikyu has completed 15 expeditions, 68 holes, and drilled a total length of more than 34 km. IODP Site C0002 has been attempted three times before (IODP Exps. 326, 338 and 348), in steps, finally reaching 3,058.5 mbsf (meters below sea floor) during 348. The objectives of IODP Expedition 358 are to penetrate toward 5,300 m, to cross the high-amplitude seismic reflector where the main plate boundary fault is believed to exist, crossing by Real-Time M-LWD (Measurement-Logging While Drilling) and WL (Wire Line) operation, monitor mud gas and cuttings, and limited core sampling of the ultra-deep fault zone. These operations are extremely difficult tasks never before achieved due to the fragile geological formation comprising the accretionary prism, and factors including the powerful Kuroshio current, location subject to typhoon approaches, and also affected by the passage of multiple cold fronts during the Winter months. This expedition is the culmination of over 20 years of planning and 11 years of IODP NanTroSEIZE drilling efforts to reach the plate interface fault system at seismogenic/slow slip depths.


The plan is to reenter the T&A’ed (temporarily abandoned) C0002F wellbore and drill to a depth of about 5,200 meters, where they expect to encounter the boundary between the Eurasian Plate and the subducting Philippine Sea Plate…

Figure 1. Schematic cross-section of NanTroSEIZE drilling program.


They will be running LWD (logging while drilling) tools to measure formation resistivity and natural gamma ray responses (just like we do in the real world), run wireline logs and core intervals above and in the plate boundary zone:

Figure 2. Schematic wellbore diagram.


Expedition result

CDEX plans to implement IODP Expedition 358: NanTroSEIZE Plate Boundary Deep Riser 4, beginning on 7 October 2018. The main expedition goal is to deepen riser hole C0002F/N/P from 3000 mbsf to the primary megathrust fault target at ~5200 mbsf, using logging-while-drilling (LWD), downhole measurements, and drill cuttings analysis extensively, in addition to limited coring intervals. This expedition will be the culmination of 10 years of IODP NanTroSEIZE deep drilling efforts to reach the plate interface fault system at seismogenic / slow slip depths.

IODP Site C0002 is the deep centerpiece of the NanTroSEIZE Project, intended to access the plate interface fault system at a location where it is believed to be capable of seismogenic locking and slip, and to have slipped coseismically in the 1944 Tonankai earthquake. This drilling target also is in close proximity to the location where a cluster of very low frequency (VLF) seismic events and the first tectonic tremor recorded in any accretionary prism setting has been found, all suggesting fault processes related to the up-dip limit of megathrust seismogenic mechanics are active here.


The drilling operation passed a depth of 3058.5 m below seafloor, the former world record for the deepest scientific ocean drilling, on 3 December.
Data on formation properties of the geological strata have been successfully obtained by logging while drilling (LWD*).
*Measurement of formation properties such as resistivity and natural gamma ray while drilling using tools integrated into the bottom hole assembly.


Start: Move to Site C0002

Phase 1: BOP setting on the ocean bottom

– After moving vessel to Site C0002, riser Hole F/N/P, launch ROV (Remote Operating Vehicle) with transponders. Deploy total of 10 transponders as an array on the sea floor.
– Retrieve corrosion cap, place corrosion cap beside the well head by ROV.
– Run BOP and Riser.
– On the rig floor, prepare drill and make up tools and check connections.

Phases 2 & 3: Ultra-deep drilling & Sample return from plate boundary

Phase 4: Onboard analysis




The Nankai Trough is known as a “Tsunami factory” and was the subject of a very detailed 3d seismic survey published in 2007 (Moore et al., 2007).

Figure 3. From Moore et al., 2007:  “Fig. 1. Location map showing the regional setting of the Nankai Trough (upper right inset). PSP, Philippine Sea Plate; KPR, Kyushu-Palau Ridge; IBT, Izu-Bonin Trench; KP, Kii Peninsula. Convergence direction between the Philippine Sea Plate and Japan is shown at the lower right.”


Figure 4. From Moore et al., 2007:  “Fig. 2. 3D seismic data volume depicting the location of the megasplay fault (black lines) and its relationship to older insequence thrusts of the frontal accretionary prism (blue lines). Steep sea-floor topography and numerous slumps above the splay fault are shown.”

Figure 5. From Moore et al., 2007:  “Fig. 3.3D data volume showing relations of in-sequence thrusts of the frontal accretionary prism (blue lines) and the younger out-of-sequence branches of the splay fault (black lines). The top of a thrust sheet that has been folded above a lateral ramp in the frontal prism is cut off by the younger megasplay fault.”

Figure 6. From Moore et al., 2007:  “Figure S1: Detail of 3D seismic inline showing the sediment accumulation on top of older thrusts (blue) and the overriding of young slope sediment by a block moving along the megasplay fault (black). Location shown in Figure 1.”

Moore et al., 2007 is available through Reaearchgate and was discussed in detail in Wired and University of Texas, Jackson School of Geosciences articles.

Who would have ever guessed that geology & geophysics can be fun and useful even when not applied to oil & gas exploration and production?


Moore, Gregory & Bangs, Nathan & Taira, Asahiko & Kuramoto, Shin’ichi & Pangborn, E & Tobin, Harold. (2007). Three-Dimensional Splay Fault Geometry and Implications for Tsunami Generation. Science (New York, N.Y.). 318. 1128-31. 10.1126/science.1147195.


101 thoughts on “The NanTroSEIZE Project: Drilling through a plate boundary in an active subduction zone.

  1. you’re right about Thwaites Glacier Cracks, Just take a Head Count of all participants…their all crackers

    • In the world of acronyms it would be helpful to provide a legend of all abbreviations and organizations referenced for those unfamiliar with the technology. Many of us here have very little exposure to this work but do appreciate the knowledge being conveyed. Many thanks.
      You might expand the interest by helping we the less knowledgeable by defining the scientific terms without going back to Geology 1001.

      • I did that in my text. I think the JAMSTEC article did so as well, although I may not have quoted the passage with the explanations. Usually, the first time an acronym is used, it is written out in parentheses: LWD (logging while drilling), BOP (blowout preventer), etc. Please let me know of any specific terms or acronyms that are unclear, and I’ll be happy to try to explain them.

        • Mr. Middleton,

          for purely sentimental reasons I would like to remind the readers that
          “The Mohorovicic Discontinuity (MOHO) marks the lower limit of Earth’s crust. It occurs at an average depth of about 8 kilometers beneath the ocean basins and 32 kilometers beneath continental surfaces.
          Mohorovicic was able to use his discovery to study thickness variations of the crust. He discovered that the oceanic crust has a relatively uniform thickness, while continental crust is thickest under mountain ranges and thinner under plains.”

          Apparently no one has ever drilled deep enough to penetrate it.

          • The Russians tried it as well with more success. The Kola superdeep borehole (Kola peninsula in eastern siberia) was an attempt to drill down to the moho, which was ~15,000 meters deep at that location. They made it to 12,262 meters before being forced to give up. Lots of interesting data was gathered, including the discovery of free water at depths where it shouldn’t exist and microscopic fossils as deep as 6.7 kilometers. Scientists theorized that the water was formed from hydrogen and oxygen atoms squeezed out of the surrounding rocks as they metamorphosed and changed phase under the incredible pressure:


    • They are or they’re. Take your pick. These typos are because stupid computers will change what you type to what they think you meant. Happens to me all the time as well.

  2. I can tell the result in advance. They will find cracks in the Thwaites glacier, lots and lots of them. There ain’t no such thing as a crack free glacier. I can say this with some confidence after “inspecting” quite a few from Svalbard to the Antarctic.

    A crack-free glacier isn’t even theoretically possible since a glacier is by definition ice that is moving. Moving ice will inevitably crack in the shallower parts where the pressure is insufficient for plastic flow. Ice is rather stiff so this can mean up to 100 meters or more.

    • But… This is probably the first time anyone has counted all of the cracks in a glacier. Whatever the result, it will be unprecedented. If successful, their next project will be to count all of the sand grains in the Sahara Desert… /Sarc

      • Yes, truly useless data.
        By the time they are done counting, the number of cracks will have changed and they can go back a begin counting again.

        Of what use is this data?

        • Yeah, but that is what modern science is abtout ! No curiosity at all – programs, programs, and programs, for ever…

      • David said exactly what I was going to post. This is so obviously going to be yet another OMG it’s worse than we though event, even before it is started we can see where they are heading.

        BTW didn’t the Russians ( USSR ) drill to about 5km in the 90’s ? Had to stop because the drills kept turning to chocolate.

        • The Kola Super-Deep borehole was deeper. But it wasn’t drilled in a subduction zone. It was drilled on the European craton.

        • I thought the stopped because that drilled into hell and discovered thousands of prophetic screaming voices, the recordings of which were only distributed either well after the events prophesied had already conveniently passed, or were so far on the future that there was no way to test them.

          Oh excuse me, they drilled into an IPCC conference. My mistake.

      • Before they move on to the Sahara, they first need to count all the holes in Blackburn Lancashire.


  3. My advice is to spring for the insurance package for the BHA, because it’s probably not coming back.

    • If they did have a neutron density tool on the BHA and got stuck… Would they still have to fish for it? A subduction zone seems like a good place to plant a source… LOL!

      • What exactly is the recommended LCM when purposely drilling through a fault and fault zone? Maybe if someone invents CWD (cement while drilling) they will get to bottom.

          • I’ve seen plenty of instances with major drilling problems due to drilling through inactive faults (complete loss of returns and subsequent hole caving) and horizontal plays where avoiding crossing a fault is key to a good well.

          • Faults can cause all kinds of problems, particularly if there is a large pressure differential across them. If you’re drilling on the down-thrown side of a fault in an over-pressured section, cross the fault, and go up-thrown into a normally pressured section, you can very easily lose the well. And you definitely don’t want to pick a casing point in a fault plane.
            However, most of the traps in the Gulf of Mexico are fault-related and most wells cut several faults and normally pressured sands juxtaposed across a fault with over-pressured shale is one of the best trap types in the Gulf of Mexico.

            You definitely want to avoid faults if you plan on a big frac job in a horizontal well… That’s the nature of shale plays: avoid structural features.

        • Worst case the drill gets stuck you snap the rod, drop a drill size and go down inside it using it as a casing. I have been on a borehole SeaGrass 1 which was the deepest hole drilled in Australia at the time and it had two different size rods stuck down the hole and they were on the final smallest rod size they had when they stopped at 2850m.

      • Nope you just declare the “source” as lost to the nuclear authority and any relevant local authority. I know 2 mines in Australia, 1 in USA and 1 in Germany that borehole data logger companies have lost neutron sources in as I worked in that industry after graduation.

  4. All they need to do is pump some silicon lubricant into the hole to get things all nice & slippery down below.

    No, I don’t really think that would do anything except maybe make the drilling go easier.

  5. cool shitz indeed.

    I was a downhole tools tech on the original JOIDES Resolution in the late 90’s – never got to do hard rock coring though. Hard work as well – two months of 12 hour shifts.

  6. I laughed at your idea it could trigger an earthquake, I assume you weren’t serious.
    The daily crust tidal stresses would dwarf any stress change a couple of inch drill hole could ever make 🙂

    • Yeah probably a joke but there will also be about 12,000 lb of hydrostatic pressure in drilling fluid at their expected depth.

    • Alas, this is now 2019.

      Science is no longer done by evaluation of data. It is done by social consensus and activist publicity.

      So WHEN an earthquake happens, during or after the drilling, THEN there will be a court case to lay blame and extract damages from whoever is associated with this project who has money. Probably the Japanese government/taxpayer…

      • This is Japan, not the US. They are a lot less lawyer-ridden, and a lot more matter-of-fact about earthquakes for obvious reasons.

    • Any earthquake that is triggered by these pin pricks, was just minutes away from being released naturally.

    • IF there is an earthquake while they are drilling… Someone, somewhere, will blame it on the drilling.

      • indeed they would. They’re probably hoping for an coincidental earthquake just so they can.

      • You underestimate the situation. If (when) there is an Earthquake — even if it is centuries from now, the BBC, NPR, Think Progress, and (probably) The Guardian will blame the drilling.

    • The removal of the material leaves a hole.
      If something breaks and steel (?) is removed,
      what is left to keep rock under pressure from moving in?
      Such has always been a problem with underground mining,
      although the scale (cross-section of the opening) is much greater.

  7. The “slumps” labeled on the graphics are reminiscent of the “ancient beaches” on the west coast of North America which have been said to represent high water caused by Global Warming events. The “slumps” may afford an alternative explanation. Of course Noah’s flood will be preferred by some.

  8. Humbug at the Deep Biosphere? Not tied to the project, but come on, you would like to go. Dr. L. Bruce Jones’ company is doing the Five Deeps (+1). Already completed the Puerto Rico Trench dive 8376 meters just a couple weeks ago.

    • That’s cool too… But the Deep Biosphere refers to microbial life living deep in the Earth’s crust. If they were drilling a deep well to look for microbial life, Deep Carbon 2019 might be cool… But they’re just having a meeting…

      The meeting will explore the significant progress and remaining questions in a variety of deep carbon science topics, such as:

      -the nature and extent of carbon in Earth’s core and the effects of extreme temperatures and pressures on carbon’s interactions with other elements
      -the physical and thermodynamic pathways in the crust and mantle that control the movements of -organic molecules and how organic molecules such as methane form in deep Earth
      -the nature of the whole Earth carbon cycle and how has it changed over Earth’s history
      -the mechanisms that govern microbial evolution and dispersal in the deep biosphere and the ecological principles that explain deep microbial community structure

  9. You are right that this is a cool project. Too bad they aren’t going all the way down to the décollement zone. Nobody has ever seen one except where it has been obducted and probably very modified like in New Caledonia.

  10. David,

    From Moore’s figures 5 and 6, that subjected plate boundary looks quite flat. It doesn’t appear to be dipping nearly as much as a sub zone on a continental margin. Perhaps because it is an island arc setting?

      • From Wikipedia…

        A study published in 2016 suggested a new parameter to determine a subduction zone’s ability to generate mega-earthquakes.[22] By examining subduction zone geometry and comparing the degree of curvature of the subducting plates in great historical earthquakes such as the 2004 Sumatra-Andaman and the 2011 Tōhoku earthquake, it was determined that the magnitude of earthquakes in subduction zones is inversely proportional to the degree of the fault’s curvature, meaning that “the flatter the contact between the two plates, the more likely it is that mega-earthquakes will occur.”[23]


        Subduction typically occurs at a moderately steep angle right at the point of the convergent plate boundary. However, anomalous shallower angles of subduction are known to exist as well some that are extremely steep.[27]

        Flat-slab subduction (subducting angle less than 30°) occurs when subducting lithosphere, called a slab, subducts nearly horizontally. The relatively flat slab can extend for hundreds of kilometers. That is abnormal, as the dense slab typically sinks at a much steeper angle directly at the subduction zone. Because subduction of slabs to depth is necessary to drive subduction zone volcanism (through the destabilization and dewatering of minerals and the resultant flux melting of the mantle wedge), flat-slab subduction can be invoked to explain volcanic gaps. Flat-slab subduction is ongoing beneath part of the Andes causing segmentation of the Andean Volcanic Belt into four zones. The flat-slab subduction in northern Peru and Norte Chico region of Chile is believed to be the result of the subduction of two buoyant aseismic ridges, the Nazca Ridge and the Juan Fernández Ridge respectively. Around Taitao Peninsula flat-slab subduction is attributed to the subduction of the Chile Rise, a spreading ridge. The Laramide Orogeny in the Rocky Mountains of United States is attributed to flat-slab subduction.[28] Then, a broad volcanic gap appeared at the southwestern margin of North America, and deformation occurred much farther inland; it was during this time that the basement-cored mountain ranges of Colorado, Utah, Wyoming, South Dakota, and New Mexico came into being. The most massive subduction zone earthquakes, so-called “megaquakes”, have been found to occur in flat-slab subduction zones.[29]

        Steep-angle subduction (subducting angle greater than 70°) occurs in subduction zones where Earth’s oceanic crust and lithosphere are old and thick and have, therefore, lost buoyancy. The steepest dipping subduction zone lies in the Mariana Trench, which is also where the oceanic crust, of Jurassic age, is the oldest on Earth exempting ophiolites. Steep-angle subduction is, in contrast to flat-slab subduction, associated with back-arc extension[30] of crust making volcanic arcs and fragments of continental crust wander away from continents over geological times leaving behind a marginal sea.

  11. Drilling is what they say they’re doing. What if they’re really trying to raise a sunken Russian submarine? Hey? Don’t look at me askance, it’s just wild enough to be true.

  12. “Drilling into the cause of an earthquake”

    Let’s understand this. One tectonic plate is sliding under another tectonic plate in what is called a “Convergent Boundary”. Current thinking, is that currents and flows in the Mantle carry/push the floating detritus called continental crust.

    This force drives one plate of continental or oceanic crust into one or more other tectonic plates. That is, incredibly massive pile of rock/minerals/metals/sediment into, and in this case under another incredibly massive pile of rock/minerals/metals/sediment.

    “Off the southwest coast of Japan, deep below the Pacific Ocean, sits the Nankai Trough, an active subduction zone where one plate of the Earth’s crust is slipping beneath another.”

    “This year, the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) began drilling into the fault. It is the “first [expedition] to drill, sample and instrument the earthquake-causing, or seismogenic portion of Earth’s crust, where violent, large-scale earthquakes have occurred repeatedly throughout history,” according to the mission’s website. Rocks collected next year will be analyzed to see how slippery or solid they are, allowing researchers to “understand more about the conditions that might lead to an earthquake on these type of fault”

    Keeping in mind exactly what tectonic collisions are, these alleged scientists are drilling into shallow fractures; ““see how slippery or solid they are“.
    Shallow fractures, i.e. faults are the result of collision forces and subject to the pressures exerted by mantle fluid movements.
    What causes the earthquakes is located much much deeper.

    Keep in mind that earthquakes, especially earthquakes that result in large tsunami, are when large sections of tectonic plate move.

    Whether the rock is slippery or solid in one borehole is a microscopic sample when what matters is the entire fault boundary conditions.
    Just saying.

    • Yes, exactly. And from the mixing, sliding together of these two incredibly massive piles of rocks/minerals/metals/sediment they will most certainly get a lot of data. But the question is, whatever can be the value of getting those data?

      They cannot ever hope to generalise much, if anything, from the results – because the factors (the proportions of rocks, minerals, sediments, etc.) appearing in this little block of the two huge masses where the drilling takes place will vary wildly from one place to another, even in the same subduction zone, let alone others in the world.

    • If I search for that on the web will I get some of this oft-mentioned Japanese “tentacle porn”, or is it a semi-respectable movie?

      • If you like bad Sci-fi with cool special effects… you’ll like it.

        If you are a Idris Elba, Ron Perlman, Max Martini or Charlie Day fan… you’ll like it.

        Most people probably don’t like it.

        • if you are a fan of GIANT MECHAS ROCKET-PUNCHING GIANT MONSTERS you’ll like it too!

          But in Pacific Rim the monsters appear through no fault of humans. They are the enemy, not ourselves in this movie.

  13. David, please restrain your self-congratulations!

    Who would have ever guessed that geology & geophysics can be fun and useful even when not applied to oil & gas exploration and production

    Where do you think all the metals come from to build your fancy drills and stuff? It comes from mines that were discovered by hard working geologists, geophysicists, geochemists, technicians and prospectors, earning about half of what they would make in the oil biz. Slogging through swamps and impenetrable forests, eaten by mosquitoes, all because we’ve been captivated by the lure of prospecting.

    And most of the plastic products made from your hydrocarbons contain up to 50 percent of mineral fillers. They all come from mines, and some of the minerals are quite exotic, like phlogopite and wollastonite.

    And let me tell you, when you see gold in drill core, there’s an experience that surely beats finding another boring old gusher. And discovering free gold in an outcrop is even better. Almost better than sex. I’ve done it three times (finding free gold in an outcrop, I mean). One of them might even be economic one day.

  14. “Who would have ever guessed that geology & geophysics can be fun and useful even when not applied to oil & gas exploration and production?”

    Good question. Your graphics give a great answer!

  15. In the 1970s to 80s one of my science hobby projects was to follow the Kola Superdeep reporting, difficult because there was a lot of Russian text and terminology. At one time I was selected to represent Australia for a 3-month scientific exchange of geochemistry in Moscow, but the Russian invasion of Afghanistan stopped that happening.
    Without my old notes to look up, it was of interest to see some of the parts played by water, be it free water circulating to depth greater than thought before, or various other water types collectively connected with metamorphism/hydration/dehydration of minerals. The changes associated with these processes can lead to better insights into what pressure really means at these great (for drilling) depths.
    I formulated a hypothesis that some shallow earthquakes (shallower than the hole depth) might be caused by the production of a newish observation from Kola, namely a zone of intense microfracturing that started a few thousand feet below surface and continued down a few thousand more until it seemed the rocks became too plastic to support the process. I surmised that the process of microfracturing, might be episodic rather than continuous as the relevant rocks were forced deeper and deeper below land surface. If episodic, I envisages a significant large rock mass, million of tons upwards, fracturing with a bang would be called an earthquake if observed. This was an addition to, not a competitor for, other explanations of earthquake formation. It need not be associated with faulting, which is nice given that many earthquakes have been located away from faults and sometimes in the middle of ‘stable’ cratons.
    But I had more serious work to do at the time and did not publish further than in an in-house journal we maintained. Has any reader chanced across a similar mechanism written up in the last 50 years? Geoff

  16. “Who would have ever guessed that geology & geophysics can be fun… ?”

    I do. My latest theory is about geophysics – Earth’s magnetic field. It’s an improvement of the dynamo theory by applying quantum mechanics and electrodynamics. I call it the X-Magneto theory because it deals with magnetic field and X is the symbol for unknown in algebra. I predict an effect that’s not yet known. That’s the official version. The personal version is I named it after Magneto of X-men :-0

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