Mount Augustine

Project Overview

Mount Augustine Island is an active andesitic stratovolcano rising 1,260 meters above lower Cook Inlet in south-central Alaska. It sits approximately 180 kilometers southwest of Anchorage. This is not a speculative thermal anomaly — it is a proven high-temperature system with a confirmed magma body, four geophysically defined prospects, and a published pre-drill resource estimate of 204 megawatts of electrical capacity at the 50th percentile.

Ignis H2 Energy Inc., in partnership with GeoAlaska LLC, designed and led two systematic exploration campaigns across the southern flank, building the most comprehensive pre-drill geothermal exploration dataset in Alaska. The science is complete. The next milestone is the drill bit.

An Exceptional Heat Source

Most geothermal projects rely on inference to characterize their heat source. Mount Augustine is different. The volcanic system beneath the island has been monitored continuously by the Alaska Volcano Observatory (USGS/AVO) since the 1980s. Independent seismic tomography, satellite monitoring, and geochemical analysis all point to the same picture:

• A partially molten magma body at 1,000–7,000 meters below sea level, estimated at approximately 870°C
• An active degassing system releasing sulfur dioxide at roughly 120 tonnes per day — a direct indicator of ongoing magmatic activity driving heat into the geothermal system
• A columnar high-temperature conduit rising from depth to approximately sea level, confirmed by 6,600+ earthquake event tomography

The heat source at Augustine is not speculative. It is one of the most thoroughly documented magmatic systems in North America.

Two Field Seasons. 273 Data Points.

Ignis and GeoAlaska designed and executed two systematic geophysical exploration campaigns on the southern flank of Augustine Island.

2023 Campaign: A 204-station gravity survey and 28-station audio-magnetotelluric (AMT) survey, led by Dr. Esther Babcock (Logic Geophysics & Analytics). Two independent methods — gravitational density contrasts and subsurface electrical resistivity — converged on the same target at approximately 1,000 meters below sea level.

2024 Campaign: A 40-station full magnetotelluric (MT) survey, led by Nick Hnotchuk, VP at KLM Geoscience LLC. Full MT extends imaging depth to 10,000+ meters, bringing the magma chamber itself within the inversion volume for the first time. This confirmed the heat source geometry and refined all four prospect targets.

3D joint inversion of all 273 data points was performed by JRG Energy Consultants Ltd. using CGG RLM-3D software — the industry standard for geothermal exploration. The result is a validated three-dimensional picture of the Augustine subsurface, from the clay cap to the magma chamber.

All permits were fulfilled and formally closed by Alaska DNR. A $100,000 State of Alaska performance bond was released in March 2025 — confirmation that all environmental obligations were met.

Four Confirmed Prospects

The 3D inversion model identified four confirmed geothermal sub-zones. Three are shallow clay cap zones on the southern flank, each defined by low-resistivity signatures below 10 ohm·m — the geophysical hallmark of a sealed geothermal system. The fourth, S DEEP, is a supercritical zone directly above the magma body at an estimated 450°C:

The planned Kamishak #1 confirmation well is located over Zone S and S DEEP — designed to test both the shallow convective reservoir and the supercritical deep zone in a single drill program.

Published Resource Estimate: 204 MWe

In 2024, Ignis H2 Energy Inc. published a peer-reviewed geothermal resource estimate in the GRC Transactions, Volume 48 (2024):

Oliver, Gasser, Oesterberg, Pennino, Craig (2024). “Probabilistic Power Density Resource Estimation of the Mount Augustine Geothermal Reservoir.” GRC Transactions, Vol. 48.

The paper reported a P50 resource of 204 MWe for the full southern flank — with a P90 of 157 MWe and a P10 of 243 MWe. A second independent analysis of the Augustine magma system by Prof. John Eichelberger (University of Alaska Fairbanks / USGS), published in GRC Transactions Vol. 47 (2023), independently validated the thermal architecture without GeoAlaska or Ignis involvement.

These are not company estimates. They are peer-reviewed science.

The Kakkonda Analogue

Every geothermal development team points to analogues. Ours is Kakkonda, Japan — an active andesitic stratovolcano-hosted geothermal field now producing approximately 80 MWe, discovered and developed under geology that mirrors Augustine:

• Same andesitic/rhyolitic volcanic chemistry
• Same MT-imaged conductor geometry (1–5 km depth)
• Same clay-rich caprock (smectite seal; verified at Augustine through XRD)
• Same liquid-dominated convective reservoir architecture

Kakkonda was drilled into the supercritical zone, where temperatures exceeded 500°C, confirming an extraordinary deep resource. At Augustine, we expect the same architecture — a scalable, high-enthalpy system capable of delivering well above the published P50 as development advances.

Alaska’s Energy Imperative

Cook Inlet natural gas currently powers roughly 70–80% of Alaska’s Railbelt grid — the interconnected system serving Anchorage, the Kenai Peninsula, and the Matanuska-Susitna Valley, with a combined load of approximately 600 MW. But Cook Inlet domestic gas supply is in terminal decline. Independent analyses point to LNG imports being required from approximately 2028, at prices that would push electricity generation costs to over $90/MWh.

Alaska’s legislature has enacted an 80% Renewable Portfolio Standard (by 2040). NREL modelling confirms the economics point to the same outcome independently of the mandate — the least-cost grid reaches approximately 76% renewable by 2040 on price signals alone.

In that context, Mount Augustine’s case is straightforward:

• No fuel price exposure. The geothermal resource is permanent; no gas supply risk.
• Dispatchable baseload. Geothermal capacity factors run 69–76%+ — compared to roughly 30–40% for Alaska wind and 10–15% for Alaska solar.
• No storage overhead. Grid operators adding intermittent renewables need battery backup. Geothermal doesn’t.
• Alaska-built. Every megawatt from Augustine is a megawatt less imported LNG — a direct domestic energy security benefit.

Commercial Milestones

Augustine’s technical credentials have attracted serious commercial interest from major Alaska energy stakeholders:

Chugach Electric Association is Alaska’s largest electric cooperative, serving approximately 144,000 customers. In May 2025 — on its own initiative — CEA’s CEO sent GeoAlaska an inbound letter of interest for offtake of up to 100% of a 200 MW Augustine geothermal project.

Alaska Data Centers LLC executed a letter of intent for a 25–50 MW geothermal power purchase agreement in April 2025 — supporting the growing demand for reliable, low-carbon power from Alaska’s expanding data center sector.

POSCO International, the global energy and commodities subsidiary of POSCO Holdings (South Korea; one of the world’s largest steel and energy companies), signed a non-disclosure agreement with GeoAlaska in March 2026, and is named in a formal State of Alaska Memorandum of Understanding signed by Governor Mike Dunleavy in May 2026. The State–POSCO MOU covers six transformational Alaska energy projects. The Mount Augustine Geothermal Energy Project is listed first.

About Cook Inlet, Alaska

Lower Cook Inlet is one of the most geodynamically active environments in North America — and among the least-explored for clean energy potential. Augustine Island sits within a well-mapped volcanic arc whose geothermal productivity is now supported by two independent exploration campaigns and a published peer-reviewed resource estimate. The surrounding Railbelt grid, serving the state’s economic core, faces an energy transition of real urgency. Augustine is positioned to be a cornerstone of that transition.