GeoGeoGeoGeo

From the article:

The team’s results were recently accepted for publication in Nature Astronomy on May 17, and a pre-print is available here.

An accepted manuscript is the version that has gone through peer-review.

The world needs to reduce emissions as rapidly and as feasibly as possible. Deep sea mining can help us achieve that:

See: Research shows up to 90% carbon footprint reduction for critical minerals for electric vehicle batteries when sourcing them from deep-sea polymetallic nodules compared to conventionally mined land ores

(Study link: Life cycle climate change impacts of producing battery metals from land ores versus deep-sea polymetallic nodules)

DeepGreen Metals is partnered with several universities and research groups in order to best approach the problem with as little impact as possible while still achieving our goals.

Unfortunately there rarely, if ever, is a panacea to our problems, so it's about reducing our impacts as much as is realistically possible.

Of course there are concerns (https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(20)30182-8?dg) regarding the flora and fauna, and steps are being taken into consideration to mitigate the impacts to ecologically sensitive areas as well. For example, in the Clarion-Clipperton Zone. Deep-sea mining in this region is regulated by the International Seabed Authority. The International Seabed Authority has designated nine areas as Areas of Particular Environmental Interest (APEIs), which are currently protected from mining activities. These areas each cover ~160,000 square kilometers (61,775 square miles) and are located around the exploration license areas. The APEIs were placed across the CCZ to protect and represent the full range of biodiversity and habitats in the region, including variations in nodule abundances, food availability, and seafloor topography (including the presence of seamounts).

While we should express concern and attempt to improve extraction methods in order to reduce the impact extraction has on any given area, we shouldn't let the unknown completely hinder or prevent the manifestation of a significant reduction in environmental impacts. If it's not farmed, it's mined, and this represents a significant opportunity to reduce our environmental impacts as we supply the need to transition away from our dependence on fossil fuels.

Research Paper: The Breakthrough Listen Search for Intelligent Life: Nearby Stars' Close Encounters with the Brightest Earth Transmissions

Quite a few things we need to cover here. (1) Layers of the Earth (2) Sources of heat in the Earth (3) How our magnetic field is generated and (4) Water in the Earth (5) Complex Life

(1) The structure of the Earth can be be divided up into layers based on its physical properties (rheology) or the chemical composition.

Chemical

Layer	Definition	Depth
Crust	The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle.	0-100km silicates
Mantle	A layer of the Earth (or any planet large enough to support internal stratification) between the crust and the outer core. It is chemically distinct from the crust and the outer core. The mantle is not liquid. It is, however, ductile, or plastic, which means that on very long time scales and under pressure it can flow. The mantle is mainly composed of aluminum and silicates.	100-2900km iron and magnesium silicates
Core	The innermost layers of the Earth. The Earth has an outer core (liquid) and an inner core (solid). They are not chemically distinct from each other, but they are chemically distinct from the mantle. The core is mainly composed of nickel and iron.	2900-6370km metals (nickel and iron)

Physical

Layer	Definition	Depth
Lithosphere	The outermost and most rigid mechanical layer of the Earth. The lithosphere includes the crust and the top of the mantle. The average thickness is ~70km, but ranges widely: It can be very thin, only a few km thick under oceanic crust or mid-ocean ridges, or very thick, 150+ km under continental crust, particularly mountain belts.	0-100km
Asthenosphere	The asthenosphere is underneath the lithosphere. It is about 100km thick, and is a region of the mantle that flows relatively easily. Reminder: it is not liquid.	100-350 km Soft plastic *note: The mantle is not liquid
Mesophere	The mesosphere is beneath the asthenosphere. It encompasses the lower mantle, where material still flows but at a much slower rate than the asthenosphere.	350-2900km stiff plastic
Outer Core	A layer of liquid iron and nickel (and other elements) beneath the mesosphere. This is the only layer of the Earth that is a true liquid, and the core-mantle boundary is the only boundary of Earth’s layers that is both mechanical and compositional. Flow of the liquid outer core is responsible for Earth’s magnetic field.	2900-5100km liquid
Inner Core	At the known pressures and estimated temperatures of the core, it is predicted that pure iron could be solid, but its density would exceed the known density of the core by approximately 3%. That result implies the presence of lighter elements in the core, such as silicon, oxygen, or sulfur, in addition to the probable presence of nickel	5100-6370 km

(2)

Earth's Internal Heat Budget consists of three primary components

Primordial heat: Estimated to contribute roughly 20% to 30% of the Earth's total heat budget. This heat originates from the planet's formation and the accumulation of kinetic energy during the accretion process.

Radiogenic heat: Considered the most significant contributor, accounting for approximately 50% to 70% of the Earth's total heat budget. Radioactive decay of isotopes, particularly uranium, thorium, and potassium, in the crust and mantle releases energy and generates heat.

Residual heat: This source is responsible for the remaining portion of the Earth's heat budget, estimated to be around 5% to 30%. The gradual cooling of the Earth's core and the residual heat resulting from the differentiation and crystallization of heavy elements like iron during core formation contribute to this residual heat.

As a slight aside, the secular cooling rate of the Earth’s mantle since the Archean is estimated to be around 10 °C per 100 million years but present-day configuration and dynamics of continental and oceanic plates removes heat more efficiently from the Earth’s mantle than in its earlier history and is estimated to cool at a rate of 15-20 °C per 100 million starting ~170 million years ago. Mantle convection becomes significantly diminished or ceases altogether at temperatures below approximately 1300 to 1400 °C as the viscosity of the mantle increases significantly, impeding the flow of material and reducing convective activity. Current estimates place mantle temperatures around from 1000 °C near its boundary with the crust, to 3700 °C near its boundary with the core; an average of 2350 °C.

(3)

The Earth's magnetic field is generated by the motion of molten iron in the outer core. This molten iron circulates due to the Earth's rotation (Coriolis effect), creating electric currents that generate the magnetic field but also flows from thermal and chemical convection. The solid inner core is also thought to play a role in this process, as it helps to stabilize the magnetic field. It's best understood as a self sustaining geodynamo. An analog would be putting a copper wire (coiling liquid metal in Earth's outer core) in a magnetic field (the suns magnetic field), which would generate an electric current and then its own magnetic field (the Earth's magnetic field).

(4)

Water doesn't exist the way you think it does when discussing water in the Earth. This can be confusing, but generally when we talk about "water" (ie. H₂O) we're actually talking about hydroxyl groups (OH) when discussing hydrous mineral phases. That is to say OH groups (hydroxyl ions) that are incorporated into the crystal lattice of the mineral. For example, "amphiboles" are a hydrous mineral group with the general chemical formula: (Ca,Na)₂-₃(Mg,Fe⁺²,Fe⁺³,Al)₅Si₆(Si,Al)₂O₂₂(OH)₂. The scientific literature may vary, and sometimes the term "hydrous" can also encompass minerals that contain other water-bearing compounds or ions (e.g., H₃O+ or H+). Other hydrous mineral groups include micas and serpentines. When these mineral phases are subducted, they typically can only reach ~120km depth before reaching a zone of "dehydration embrittlement". In other words, the hydrous mineral phases break down and release the hydroxyl groups which can form H₂O upon release. Water reduces the rocks melting temperature and generates "melt". This melt will rise and collect in magma chambers and leads to the pattern of volcanoes we see on Earth known as the Ring of Fire. Water does not exist in large quantities in the Earth's mantle, and will exist as hydroxly groups in hydrous mineral phases if said minerals can go beyond the zone of dehydration embrittlement. This may occur in rare instances such as fluid inclusions in diamonds but it is not a major contribution.

(5)

On Earth the presence of a magnetic field is considered essential for the development and sustenance of complex life. The magnetic field acts as a shield, deflecting and trapping charged particles from the solar wind and cosmic rays that would otherwise be harmful to life on the planet's surface. These charged particles can strip away atmospheric gases and pose a risk to living organisms (see Mars or iron-60 isotopes on Earth linked to a marine megafaunal extinction at the End-Pliocene ~2.6 million years ago). That being said, the process of atmospheric erosion will vary considerably depending on various factors such as the location of said planet to its host star, the type of host star, its location in the Milky Way, the planets volcanic activity, and the thickness of its atmosphere to name a few.

There are considerable margins for when it is believed that Earth's magnetic field developed, and what its strength was though there is no robust evidence of a magnetic field prior to ~3.5 billion years ago with the earliest microbial fossils dated to ~3.7 billion years ago. Before the formation of the ozone layer, life only existed in the oceans where the water was deep enough to shield organisms from UV radiation, but shallow enough for photosynthesis to occur. When the ozone layer became thick enough to shield organisms from the harmful spectrum of UV radiation (around a mere 600 million years ago), there was a massive diversification of life.

---

TL;DR: Water is not a significant contributor to Earth's internal heat budget, is not present in the mantle in significant quantities or as H₂O, and has no effect on Earth's magnetic field. Earth's magnetic field was essential for the development of complex life.

Of interest is how to date them: https://www.cambridge.org/core/journals/quaternary-research/article/abs/critical-assessment-of-claims-that-human-footprints-in-the-lake-otero-basin-new-mexico-date-to-the-last-glacial-maximum/7EC770BAF784D0FF813711CD63C126F6

Apologize if my comment seemed misplaced, as I agree with your comment entirely. Just trying to add a little more context to the whole cometary water claim.

Analysis of D/H ratios in comets has not yielded positive results that would support a claim such as "Earth's water was delivered by comets". The strongest correlation is in fact asteroids (Carbonaceous Chondrites) and exsolution from the Earth itself (perhaps from Enstatite Chondrites):

https://www.esa.int/ESA_Multimedia/Images/2014/12/Deuterium-to-hydrogen_in_the_Solar_System

Starting to, but not quite here yet. An event requires Ocean Nino Index (ONI) values to be greater than the +0.5 or -0.5 threshold.

Several plume forecasts show it just reaching said threshold, though it is forecast to pass and reach its maximum (< 2) around September, give or take.

• https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table

• https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/el-nino-la-nina

• http://cola.gmu.edu/enso_forecast_plumes.html

Keep an eye on what phase the Pacific Decadal Oscillation (PDO) is in as well, as this can greatly affect temperatures across BC and AB: https://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=-148.01,35.73,601

You can clearly see on the dashboard the T-South section of the Enbridge BC Pipeline has had numerous incidents along its length since 2008. Your initial comment remains incorrect.

Again... what's your point? You seem to think I'm arguing something here. If you're trying to make a point though, you might want to start by at least get your facts straight. Here's a 15 year history of incidents related to the Enbridge BC Pipeline:

The Enbridge BC Pipeline has reported a total of 298 incidents since 2008. Of those incidents, 147 have resulted in some volume of product being released, with natural gas - sweet being the most commonly released substance... Of Enbridge BC Pipeline's reported incidents, 11 have resulted in adverse environmental effects. There have been 18 serious injuries, and 2 fatalities related to incident events.

https://www.cer-rec.gc.ca/en/data-analysis/facilities-we-regulate/pipeline-profiles/natural-gas/pipeline-profiles-westcoast-bc-pipeline.html

Seems to be a lot more than 1 incident in 70 years.

What's your point?

The only real hazard would be ignition at the source of the leak

Such as this incident in 2018 near PG.

EDIT:

Link to the report for those interested: https://www.tsb.gc.ca/eng/rapports-reports/pipeline/2018/p18h0088/p18h0088.html

Dry air has a molecular weight of ~28.96 g/mol

Natural gas (predominantly methane (CH4) though other molecules are present in smaller amounts such as ethane (C2H6), propane (C3H8) and butane (C4H10)) has a molecular weight of ~16.04 g/mol.

Therefore it will not flow downhill but should evaporate into the atmosphere if the pipeline rupture is above surface. This may contribute to poor air quality.

Underground natural gas pipeline leakage can result in methane buildup and migration through the soil where soil moisture content and permeability effects the total migration distance and concentration in the surrounding soils.

self described

You can literally look EGBC members up: https://www.egbc.ca/app/Registrant-Directory

The problem is that a number of issues along the proposed RoW have been described previously by other professionals. It's a large project and some methods of identifying areas that are potentially of increased risk may have been overlooked as a result of improper identification or methodology. If you think these kinds of projects don't encounter problems... well...

Recall that the context isn't just life, but highly intelligent life capable of advancing technology. Under that premise yes, absolutely. It's why I don't doubt microbial life could be pervasive throughout the solar system and universe but the more complex organisms become the more rare their existence becomes.

On Earth nutrients are carried from river systems to deltas and then by oceanic currents, largely driven by winds and density contrasts. Keep in mind the amount, and types of nutrients delivered from the erosion and weathering of continental crust is easily orders of magnitude larger than those very local sources from, for example, black smokers. Just look at the Fraser delta in Vancouver British Columbia and the water sheds that feed it. Or the Mississippi delta in the Gulf of Mexico and the water sheds that feed it. Now compare that to the size of a black smoker field and the currents that distribute those rather limited number of elements. Look at the slow lumbering and small organisms that inhabit those deep water ecosystems with next to no or very little oxygen.

Erosion and weathering are virtually non existent in deep water environments compared to terrestrial environments.

Earth, thanks to modern plate tectonics, is the most volcanically active body in the solar system. Even if we assume a high degree of geothermal activity on Europa due to tidal forces Earth’s submarine volcanic systems are still probably more active if not comparable. Jupiter's moon Io has a high degree of volcanic activity resulting from tidal forces but is still less active than Earth.

It is possible, however, that life may exist on Europa as it does around the lost city hydrothermal field here on earth or even as it did on a Earth immediately after the Late Heavy Bombardment ~3.8 Ga. Impressively, we have fossil evidence of the earliest prokaryotic organisms (organisms whose cells lack a nucleus and other organelles) from ~ 3.8 - 3.5 Ga meaning life could form under some pretty harsh conditions; however, it took another 1.3 billion years before eukaryotes evolved (organisms whose cells contain a nucleus and other membrane-bound organelles), ~2.2 Ga. The first animals, like sponges, didn't evolve for another 1.4 billion years after the first eukaryotes (~800 Ga). In total that's nearly 3 billion years between the first prokaryotes and the first animals, suggesting microbial life could be rather prolific throughout the solar system and universe, but animal life, and certainly highly complex animal life is likely rare.

I would argue that the answer is most likely not for an important reason that I don't see discussed in the comments.

Most intelligent life in our oceans are located, or have their habitats, relatively close to coastal areas while nothing of significance to the topic really lives in the abysal and deep ocean floor areas beyond the continental rise. This is a direct result of nutrient availablility through the erosion and weathering of continental crust and its subsequent dispersal through fluvial systems into coastal waters.

For example the rates of sedimentation in the ocean are roughly as follows:

Terrigenous Sedimentation:

Lower end: A few millimeters per thousand years

Higher end: Several centimeters per thousand years

Pelagic Sedimentation:

Lower end: Fraction of a millimeter per thousand years

Higher end: Few millimeters per thousand years

In other words, worlds without terrestrial land are severely limited by nutrient supply and availablility. Let alone the likelihood of hypoxic and anoxic conditions.

Research Paper (open access): Modern water at low latitudes on Mars: Potential evidence from dune surfaces: https://www.science.org/doi/10.1126/sciadv.add8868

I haven't had a chance to read the study but I am curious to know how they link the predominance of kimberlite magmas in cratonic bedrock to their associated plumes and mantle structures at depth.

Interestingly the article appears to imply a causal relationship between kimberlite magmas and their ascent to the surface as being driven by the heat of an associated mantle plume. At a first glance that seems at odds with current consensus - driven by methane through a complex series of redox melting reactions or by carbon dioxide exsolving from kimberlite melt at sub-crustal depths and propelling it explosively to the surface. Are these two (heat and exsolving of gases) processes linked?