Author: Steingrimur Thorbjarnarson

I am a geologist, graduated from the University of Iceland, and taught geology for a few years. I have gained some knowledge about Earth's inner structure, so I provide this website as my contribution to answer one of the greatest questions remaining within the realm of geoscience. Experiments show that the mantle should form convection rolls when close to the melting point. I took this literally, and calculated the dimensions and shape of these mantle convection rolls. Then I compare that model with the surface. This makes it possible to provide many interesting examples about geology found on my blog.

Main Sections of the Ring of Fire (clockwise)

Geometrical Presentation of the Ring of Fire.

1. Aleutian Islands and Alaska Peninsula

Classic subduction arc
Aleutian Trench
Pacific Plate subducting northward beneath North America
Shows segmentation and slab variability

2. Queen Charlotte–Fairweather Fault System

Major transform boundary
Right-lateral motion between Pacific and North American plates
Transition from subduction to strike-slip

3. Cascadia

Cascadia Subduction Zone
Juan de Fuca Plate subducting beneath North America

4. California

Dominated by San Andreas Fault and California Bay
Transform motion
High seismic activity, limited volcanism

5. Central America

Middle America Trench
Cocos Plate subducting beneath Caribbean Plate
Well-developed volcanic arc

6. Peru

Part of the Andean subduction system
Nazca Plate subducting beneath South America

7. Chile

One of the most active subduction zones on Earth
Deep trench and extensive volcanism
Site of major megathrust earthquakes

8. Antarctic Peninsula

Continuation of Andean-type subduction
Interaction between Antarctic, Scotia, and South American plates
Complex tectonic transitions

9. Antarctica

More diffuse tectonic setting
Volcanoes

10. Antarctica to Mid-Ocean Ridge

Transition from subduction-related systems to divergent boundaries
Includes spreading centers of the Southern Ocean

11. Mid-Ocean Ridge to New Zealand

Pacific-Antarctic Ridge
Seafloor spreading
Transition toward complex plate boundary near New Zealand

12. Tonga–Kermadec Subduction Zone

Tonga Trench
Among the fastest and deepest subduction zones
Very steep slab geometry

13. Trenches Connecting Guinea and Tonga

Region including New Hebrides (Vanuatu) subduction system
Complex interaction of microplates
Highly active volcanism and seismicity

14. Philippine Trench

Philippine Trench
Westward subduction of the Philippine Sea Plate
Multiple interacting subduction systems nearby

15. Ryukyu Trench

Ryukyu Trench
Subduction beneath the Ryukyu Arc
Back-arc extension in the Okinawa Trough

16. Kuril Islands and Kamchatka

Kuril-Kamchatka Trench
Classic Pacific Plate subduction beneath Eurasia
Highly active volcanic arc

Additional Key Reference Points

These are important markers in your framework, linking geometry and deeper structure:

A) Western Equatorial Point

Key symmetry point along the equator
Potential reference for large-scale mantle structure

B) Eastern Equatorial Point

Counterpart to the western point
Defines global-scale division of the Pacific system

C) South Island

Transition between subduction and transform (Alpine Fault)
Oblique plate motion

D) Yellowstone

Intraplate volcanism
Often linked to deep mantle processes

E) North Island

Active subduction (Hikurangi margin)
Volcanic arc and back-arc extension

F) San Andreas Fault

Major transform boundary
Separates Pacific and North American plates

G) Challenger Deep

Deepest point in the oceans
Extreme subduction environment

H) Hawaii

Intraplate hotspot chain
Indicates deep mantle upwelling

J) Japan

Complex multi-trench system
Interaction of Pacific, Philippine, and Eurasian plates

This represents a highly comprehensive description of the Ring of Fire. The underlying causes can be considered from several perspectives. One key factor is the presence of two reference points along the equator, which appear to define the foundation of a large-scale symmetric structure. Rather than forming a perfect circle, this structure resembles a mirrored ellipse, skewed westward in the Northern Hemisphere and eastward in the Southern Hemisphere. This asymmetry may reflect the influence of Earth’s rotation, which affects large-scale flow patterns in a consistent manner. In contrast, a non-rotating Earth would be expected to produce a more uniform, circular geometry.

The boundaries of both the outer and inner parts of this system can also be interpreted within this framework. Not only do the equatorial reference points appear to play a central role, but comparing the details with additional control points throughout the mantle convection system, it seems like they too contribute to shaping the overall structure.

When examining specific details, further intriguing patterns emerge. Along the minor axis, key features such as New Zealand, the San Andreas Fault, and Yellowstone are aligned. Along the major axis, systems such as Japan stand out. A north–south axis can be associated with Hawaii, while the Challenger Deep appears to lie along a principal line within the inner structure of the system. Even the configuration of mid-ocean ridges shows a degree of resemblance to segments of this broader circular or elliptical pattern.

These recurring geometric relationships suggest that the Ring of Fire may reflect a deeper, organized structure within the Earth system, and horozontally the global arrangement is clearly not random at all. Saying ‘not random’ is an inverse scientific statement 🙂 This makes people curious, and this makes people surprised. At the same time, this indeed does raise important questions about the mechanisms responsible for producing such large-scale coherence.

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Aleutian Subduction as a Function of Mantle Convection

April 13, 2026 Steingrimur Thorbjarnarson

The Aleutian Trench extends from Alaska to Kamchatka, forming the northern segment of the Ring of Fire. Along this boundary, the Pacific Plate is subducted northwards beneath the adjacent plate.

However, the character of this subduction differs from many other regions of the Pacific. The slab appears less continuous and less regularly organized than in classic subduction zones. Within the convection rolls model, this can be explained by the direction of plate motion: northward drift causes the plate to move largely parallel to the underlying convection rolls rather than perpendicular to them. As a result, the rolls tend to deflect and segment the slab, producing divisions and irregularities.

What remains remarkably consistent, however, is the position of the subduction zone itself. As seen on the model map, the Aleutian subduction zone extends between two major division lines in the lower mantle. Furthermore, its Alaskan end coincides with a crossing of two such deep-mantle structures. These intersections may act as anchoring points, helping to define the outer limits of the entire Ring of Fire.

At first glance, such consistency might be dismissed as coincidence. Yet similar patterns recur around the Pacific margin, collectively forming the well-known Ring of Fire. In the case of the Aleutian system, the subduction zone not only spans between two division lines but also aligns with additional crossings at slightly lower latitudes. These points can be interpreted as key nodes—together with corresponding structures in the upper mantle—controlling the downwelling process responsible for subduction of the Pacific Plate along approximately 51°N.

Consistency between Ring of Fire and circular form.

1. Alaska – Cascades 2. San Andreas – Central America 3. Eastern equatorial point – South America 4. Antarctica 5. Antarctica – New Zealand 6. New Zealand – Indonesia (western equatorial point) 7. Phillipine Sea Plate 8. Kuril Islands – Aleutian Islands.

In this framework, subduction operates in a manner comparable to regions where plates move predominantly east–west: the plate is forced to bend, descend, and penetrate into the mantle. This process is supported by convection rolls that are arranged more or less perpendicular to the direction of motion, even if only locally. Antarctica represents a further key case study within the broader Ring of Fire system. Here, the main point of interest is the striking consistency between the convection rolls model and the large-scale circular geometry observed around the Pacific margin.

The recurring geometric relationships observed around the Pacific provide a compelling basis for comparing the convection rolls model with real-world tectonic systems.

.https://en.wikipedia.org/wiki/Aleutian_subduction_zone#/media/File:EQs_1900-2016_aleutian_tsum.png

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History of the Common Sense of Plate Tectonics

April 10, 2026 Steingrimur Thorbjarnarson

At the start of the 20th century, geology faced a fundamental problem:
continents appeared to move, but no physically acceptable mechanism existed.

In 1912, Alfred Wegener presented the theory of continental drift. He argued that continents had once formed a single landmass (Pangaea) and later separated. His evidence — fossil correlations, matching geological structures, and continental fit — was compelling. However, Wegener could not provide a convincing driving force, and his ideas were widely rejected.

Meanwhile, a crucial breakthrough came from physics. Between 1896 and 1905, building on discoveries by Becquerel and the work of Ernest Rutherford, scientists established that radioactive decay produces heat. This insight solved a major constraint: Earth was not simply cooling, but continuously generating internal heat. By the early 1900s, it became clear that Earth possessed a long-lived energy source capable of driving internal processes.

The next step was to understand how that the radioactive decay provided primary energy. In 1928–1929, Arthur Holmes proposed that heat inside the Earth drives mantle convection. He suggested that hot material rises and cooler material sinks, forming large-scale circulation patterns. Crucially, Holmes connected this internal flow to the drift of continents — proposing that convection currents could carry them. This was the first physically plausible mechanism linking Earth’s internal energy to surface motion.

However, direct evidence was still lacking — especially beneath the oceans, which remained largely unexplored.

That changed after World War II. Between 1950 and 1962, advances in sonar mapping revealed mid-ocean ridges, deep-sea trenches, and the global structure of the ocean floor. In 1962, Harry Hess proposed seafloor spreading: new oceanic crust forms at mid-ocean ridges, moves outward, and is eventually consumed at subduction zones.

Soon after, in 1963, Vine and Matthews demonstrated symmetrical magnetic striping on the ocean floor, providing strong confirmation that seafloor spreading was real and continuous.

The Synthesis (Late 1960s)

By 1967–1968, these ideas converged into the modern theory of plate tectonics:

Radioactivity (1896–1905) → provides the internal heat
Convection (Holmes, 1928–29) → organizes that heat into motion
Seafloor spreading (Hess, 1962) → reveals how crust is created and recycled
Magnetic evidence (1963) → confirms continuous movement

The Earth was finally understood as a dynamic system, not a static one.

The Physical System

The emerging model describes a coupled system:

Heat from radioactive decay drives mantle convection
Convection creates organized flow within the mantle
This flow moves rigid lithospheric plates
Plates:
- diverge at ridges
- converge at subduction zones
- slide past along transform faults

Continents are therefore not independent — they are embedded in moving plates, which reflect deeper flow patterns.

The Deeper Insight

The key realization of the 20th century is that Earth behaves as a thermally driven engine:

Energy source → radioactive decay
Transport mechanism → convection
Surface expression → plate tectonics

What began as disconnected observations became a unified physical framework linking nuclear physics, fluid dynamics, and geology.

Extending the Framework

The classical model (Holmes → Hess → plate tectonics) established that convection drives tectonics.

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The Mantle Convection Rolls Grid

April 7, 2026April 7, 2026 Steingrimur Thorbjarnarson

Understanding the geological processes in Iceland and elsewhere, both tectonic drift and mantle currents have to be considered.

This map shows it all, tectonic drift vectors from the National Land Survey of Iceland. The grid of division lines superimposed on this map shows the outlines of convection rolls below Iceland. The convection rolls can not be measured yet, due to several reasons.

5 Core Factors + 2 Observables:

5 CORE FACTORS (causes in the mantle)

Temperature

Composition (chemistry)

Pressure / depth

Mineral phase (structure)

Partial melt / fluids

2 OBSERVABLES (what we measure)

Seismic velocity (Vp, Vs)

Attenuation (Q)

An addition to low resolution, these factors make it too complicated to get a clear picture of the vertical structure aspects of the mantle. But the methods used here to make the convection rolls model are a shorter way, thereby deducting these lines before modern sensors, relevant AI and other types of technology provide direct observation opportunities.

Each of those lines shows the division between two convection rolls, found below Iceland at different depth, but all of them affect the tectonic plates of N-America and Eurasia. The first demonstration is how the volcanic zones follow the scope of the convection rolls. The only way to explain this consistency is finding out how those division lines affect the tectonic plates (and the crust). Ignoring this consistency would be wrong.

This leads us to consider further what happens down below, within the asthenosphere, the transition zone of the mantle, and the lower mantle. These lines are really narrow and sharp, so the way magma ascends through the tectonic plate should be analysed. The only way is the accumulation of martial melt exactly where the division lines are found, a mechanism of the convection rolls to release the partial melt there and make it possible for the lines of ascending magma to proceed all the way upwards, a distance of 120 km.

With this in mind, a myriad of geological features can be explained, hitherto hidden and not understood.

As can be seen on the map, the tectonic drift vectors are remarkably parallel to the convection rolls. This is a mathematical coincidence, found at the starting point of tectonic drift of the two plates. Farther out, this consistency is not seen, as the two plates drift and rotate in their independent ways.

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Partial Melting of Peridotite and the Subsequent Flow of Basalt Towards the Surface

April 6, 2026 Steingrimur Thorbjarnarson

It can be difficult to explain how peridotite undergoes partial melting to produce basalt, and how that basalt subsequently migrates upward through the lithosphere. Within the asthenosphere, there are no open voids or fractures through which melt can simply flow. Therefore, an important question is how the melt becomes concentrated and how it is transported upward through the ductile portion of the tectonic plate.

Partial melting of peridotite and the subsequent flow of basalt towards the surface

This schematic proposes that partial melting occurs in regions where pressure is reduced due to tectonic movements above. In addition, the interaction of adjacent convection rolls should combine their thermal influence with symmetric heat radiation, creating localized zones where conditions are favorable for partial melting.

The upward transport of melt through the ductile lithosphere must be assisted by some focusing mechanism, allowing it to move in narrow, directed pathways. Evidence for such pathways is found in the sheeted dike complexes within ophiolites, which could represent the uppermost expressions of these ascending melt channels.

One possible physical analogy is the Munroe effect, in which energy is focused into a narrow jet capable of penetrating solid material. In this context, a comparable mechanism might involve the concentration of thermal energy or stress along specific lines or zones, enabling sustained, directed upward flow through the ductile material. The symmetrical flow lines do then have to provide an appropriate “standoff”, a key concept regarding the physical preconditons of Munroe effect. Some might say that explosion on one hand and a steady process on the other hand are not comparable, but considering that the process is the same, even though one is short term, the other long term, the results will be similar.

Beneath oceanic plates, where the lithosphere is approximately 100 km thick, such focused flow could allow basaltic melt to traverse the ductile region. Upon reaching the brittle upper lithosphere, the melt would then exploit fractures and fissures, continuing its ascent.

Finally, as pressure decreases, volatiles exsolve from the magma, causing rapid expansion and increased buoyancy, which further drives the magma toward the surface or the seafloor.