Katla (Mýrdalsjökull)

Seismicity by period · derived statistics from Skjálftalísa (Icelandic Met Office)

Status (automatic)

In the last 24 hours, 17 earthquakes were recorded at Katla, indicating slightly higher activity than usual for this area but similar to the past week. The activity is characterized by distributed background seismicity rather than swarms, and results are automatic preliminary data. GNSS data indicate subsidence of approximately 14 mm/year after seasonal correction. Further details on trends and measurements are available below.

VONA (Katla): Green (was: Yellow, 2024-07-29) · source

VONA = Volcano Observatory Notice for Aviation; the official Met Office colour code for aviation. Independent of Skjálfti's automatic analysis.

Depth — 3D and cross-section Katla (Mýrdalsjökull) · last 90 days

Each dot is an earthquake, depth as the third dimension — Katla (Mýrdalsjökull), last 90 days. Drag the 3D view to rotate; point at a dot for details.

3D (rotatable) · depth ×2.5

Cross-section — distance along profile (km) vs depth (km)

Map (top view)

<24 klst2–7 dolderunconstrained depthsize ∝ magnitude (M)

⚠ Preliminary depths, unreliable (automatic Met Office solutions; depth often poorly constrained). events with unconstrained (default) depth shown as open rings — not real structure. For illustration, not analysis.

🕰️ Last eruption / event — ~108 years ago

The 1918 Katla eruption (1918-10-12). Jökulhlaup over Mýrdalssand added ~4 km of coastline over several days. The current 108-year pause is among the longest in Katla's known history — it typically erupts every 40-80 years.

Powerful central volcano beneath Mýrdalsjökull, known for explosive eruptions and large glacial floods. The last major eruption was in 1918; persistent seismicity beneath the glacier. (overview — more at vedur.is) · circle on the map = rough outline of the system (radius).

Subglacial system: a subglacial eruption can cause a jökulhlaup (sudden glacial meltwater flood) with little warning, and volcanic gases (incl. SO₂, CO₂) can be dangerous near vents and may pool in hollows. These are standing features of the system, not a sign of an imminent eruption.

📜 Did you know?

The current 108-year pause is among the longest in Katla's known history (it normally erupts every 50-100 years). The Eldgjá eruption ~934 AD belongs to the Katla system — 18 km³ of lava, one of the largest lava eruptions in historical time on Earth. The 1918 eruption added about 4 km to the coast at Mýrdalssand over several days.

Historical eruptions in the system — points colored by size, blue circle shows where we are now in time.

❓ What if Katla erupts tomorrow?

Timeline: Historical warning from GPS and seismic data is 1-3 hours, but a jökulhlaup can start within a minute of subglacial eruption breach. Jökulhlaup: Most likely down Mýrdalssand (possibly down Markarfljót or Skálm). Peak flow can reach 100,000-400,000 m³/s (1918: ~300,000 m³/s; 1755: 200,000-400,000 m³/s) — comparable to the Amazon. Ring Road closes between Vík and Skógasandur for days to weeks. Ash: Wind-dependent. SW wind (common): Reykjavík spared, Suðurland worst affected. NW wind: ash reaches Faroes and Scotland. Aviation: North Atlantic flights may stop for days to weeks (cf. Eyjafjallajökull 2010). Sources: 1918 eruption added ~4 km to the Mýrdalssand coast over several days. Met Office hazard assessment (vedur.is/vatnafar/haettumat-floda).

This is not a forecast. Based on historical experience and official hazard assessments from the Met Office / Civil Protection.

Jökulhlaup history (historical renewal model + Bayesian update)

Last known flood (Múlakvísl): 2024-08-15, 664 d ago. Median interval between floods: ~3.0 yr (1111 d, n=5) · historically ~1 in 50 within 6 mo from a state like this (n=5).

Active signals now:

Skjálfta-aukning (×2.0) — 16.6/d vs 3.6/d (sl. 14d)

Active signals raise the rough baseline — from ~1 in 50 toward ~1 in 25 over the next 6 mo. The multiplier (×2.0) is a rough estimate, not a measured probability.

Likelihood ratios are illustrative — not from peer-reviewed Iceland-specific research. Indicator, not forecast.

Note: The Met Office does not publish open realtime water-level/conductivity data. Realtime flood monitoring requires VPN/agreement with Veðurstofa (vmkerfi.vedur.is).

AUST step detection — 6 drops ≥ 15 mm in past 2 yr (May-Oct; winter snow filtered). Each drop = ice-shell subsidence, possible jökulhlaup signal. Latest: 2025-10-11 (-17 mm).

24 h48 h7 d30 d365 d2 y

Points = earthquake locations in the selected window, coloured by magnitude: ● M3+ · ● M2+ · ● smaller (a sample if more than 800).

Earthquakes

Largest

M2.4

M3,0+

Depth range

0–8 km

Earthquakes over time

Cumulative count · 25 earthquakes · total moment ≈ M2.5 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

Largest

M2.4

M3,0+

Depth range

0–8 km

Earthquakes over time

Cumulative count · 33 earthquakes · total moment ≈ M2.5 · count moment

No significant hypocenter migration — activity is stationary (R²=0.12, n=33); no sign of a propagating dike. Migration shows automatically if R²≥0.30.

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

159

Largest

M2.6

M3,0+

Depth range

0–24 km

Earthquakes over time

Cumulative count · 159 earthquakes · total moment ≈ M3.0 · count moment

No significant hypocenter migration — activity is stationary (R²=0.01, n=159); no sign of a propagating dike. Migration shows automatically if R²≥0.30.

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

300

Largest

M2.6

M3,0+

Depth range

0–24 km

Earthquakes over time

Cumulative count · 300 earthquakes · total moment ≈ M3.1 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

1653

Largest

M3.0

M3,0+

Depth range

0–24 km

Earthquakes over time

Cumulative count · 1653 earthquakes · total moment ≈ M3.6 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Gutenberg-Richter b ≈ 1.21 ± 0.09 (i.e. likely 1.13–1.30, M≥1.7, n=117)

Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.

Earthquakes

2320

Largest

M3.0

M3,0+

Depth range

0–24 km

Earthquakes over time

Cumulative count · 2320 earthquakes · total moment ≈ M3.7 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Gutenberg-Richter b ≈ 1.14 ± 0.07 (i.e. likely 1.07–1.21, M≥1.7, n=176)

Depth is automatic and uncertain; earthquakes alone do not show magma movement — deformation (GPS) and gas are needed. Grey points: automatic fixed-depth values. b-value computed for M≥1.5 (automatic magnitudes make lower completeness unreliable). Preliminary data.

Glossary & magnitude scale →

Uplift — GNSS deformation

AUST — land subsiding ~15 mm/yr (árstíða-leiðrétt) · long-term +37 mm/yr (MIDAS)

REYK (Reykjavík) — reference ~-2 mm/yr

Show all stations (N/E/Up + cluster)

AUST — horizontal and vertical displacement (N · E · Up) past 365 d, mm from first reading

Up = land rising (possible magma accumulation), down = subsidence. From Nevada Geodetic Lab (third-party processing, ~3-week lag, latest 2026-05-17). Interpreted deformation: Icelandic Met Office.

🌊 Volcanic tremor — Volcanic tremor is currently at a normal baseline, but due to unreliable weather models f…

IMO tremor plot (station god). Most of the signal is weather and surf — not eruption confirmation. All stations: vedur.is.

Weather now: wind 8 m/s (Reynisfjalli) — moderate.

Volcanic tremor is currently at a normal baseline, but due to unreliable weather models for this inland station, it should only be compared against recent days. (AI)

Band analysis past 9 days (from digitized RSAM values). High 2-4 Hz + low 0.5-1 Hz = possible magma-movement signal; high 0.5-1 Hz without 2-4 Hz = weather/surf.

Earthquakes in the system

Time (UTC)	Mag	Depth	Area
2026-06-10 09:03	M0.4	5.2	Mýrdalsjökull (Katla)
2026-06-10 09:03	M-0.4	5.2	Mýrdalsjökull (Katla)
2026-06-09 20:35	M1.3	8.2	Mýrdalsjökull (Katla)
2026-06-09 20:25	M-1.8	5.2	Mýrdalsjökull (Katla)
2026-06-09 20:12	M-1.5	5.2	Mýrdalsjökull (Katla)
2026-06-09 19:16	M-0.7	5.2	Mýrdalsjökull (Katla)
2026-06-09 18:57	M0.4	1.1	Mýrdalsjökull (Katla)
2026-06-09 18:29	M-0.9	5.2	Mýrdalsjökull (Katla)
2026-06-09 18:20	M-0.9	5.2	Mýrdalsjökull (Katla)
2026-06-09 18:16	M1.8	1.1	Mýrdalsjökull (Katla)
2026-06-09 18:16	M1.6	1.1	Mýrdalsjökull (Katla)
2026-06-09 18:07	M-0.7	6.4	Mýrdalsjökull (Katla)
2026-06-09 18:04	M-0.1	2.6	Mýrdalsjökull (Katla)
2026-06-09 18:00	M0.7	1.1	Mýrdalsjökull (Katla)
2026-06-09 18:00	M1.0	0.0	Mýrdalsjökull (Katla)
2026-06-09 17:58	M2.2	1.1	Mýrdalsjökull (Katla)
2026-06-09 17:58	M2.4	8.4	Mýrdalsjökull (Katla)
2026-06-09 17:55	M0.3	4.5	Mýrdalsjökull (Katla)
2026-06-09 17:55	M0.3	3.6	Mýrdalsjökull (Katla)
2026-06-09 17:53	M0.9	1.1	Mýrdalsjökull (Katla)
2026-06-09 16:11	M-0.1	5.2	Mýrdalsjökull (Katla)
2026-06-09 13:28	M-1.0	4.6	Mýrdalsjökull (Katla)
2026-06-09 13:28	M-0.8	5.2	Mýrdalsjökull (Katla)
2026-06-09 13:10	M0.7	3.1	Mýrdalsjökull (Katla)
2026-06-09 11:09	M0.6	7.3	Mýrdalsjökull (Katla)
2026-06-09 07:04	M0.9	1.1	Mýrdalsjökull (Katla)
2026-06-09 07:04	M0.6	0.0	Mýrdalsjökull (Katla)
2026-06-09 06:53	M-0.9	5.3	Mýrdalsjökull (Katla)
2026-06-09 06:52	M-0.1	1.1	Mýrdalsjökull (Katla)
2026-06-09 00:59	M0.8	5.3	Mýrdalsjökull (Katla)
2026-06-08 16:54	M0.2	2.3	Mýrdalsjökull (Katla)
2026-06-08 13:26	M-1.0	5.2	Mýrdalsjökull (Katla)
2026-06-08 09:38	M-0.2	5.2	Mýrdalsjökull (Katla)
2026-06-08 06:56	M0.1	2.5	Mýrdalsjökull (Katla)
2026-06-08 06:56	M0.4	1.1	Mýrdalsjökull (Katla)
2026-06-08 06:26	M0.1	5.2	Mýrdalsjökull (Katla)
2026-06-08 05:08	M1.8	0.0	Mýrdalsjökull (Katla)
2026-06-08 04:33	M0.1	0.9	Mýrdalsjökull (Katla)
2026-06-08 04:33	M0.5	3.3	Mýrdalsjökull (Katla)
2026-06-07 22:53	M0.1	1.1	Mýrdalsjökull (Katla)
2026-06-07 22:51	M1.0	1.1	Mýrdalsjökull (Katla)
2026-06-07 22:41	M0.0	5.8	Mýrdalsjökull (Katla)
2026-06-07 22:33	M1.2	5.2	Mýrdalsjökull (Katla)
2026-06-07 22:32	M0.2	2.9	Mýrdalsjökull (Katla)
2026-06-07 22:00	M-1.5	5.2	Mýrdalsjökull (Katla)
2026-06-07 20:13	M0.2	5.2	Mýrdalsjökull (Katla)
2026-06-07 19:27	M-0.3	1.1	Mýrdalsjökull (Katla)
2026-06-07 18:48	M0.1	4.9	Mýrdalsjökull (Katla)
2026-06-07 18:47	M-0.7	1.1	Mýrdalsjökull (Katla)
2026-06-07 18:46	M1.2	3.4	Mýrdalsjökull (Katla)
2026-06-07 18:46	M1.2	3.4	Mýrdalsjökull (Katla)
2026-06-07 18:46	M-1.4	5.2	Mýrdalsjökull (Katla)
2026-06-07 16:05	M-1.7	5.2	Mýrdalsjökull (Katla)
2026-06-07 16:04	M-0.6	3.0	Mýrdalsjökull (Katla)
2026-06-07 15:58	M1.0	4.4	Mýrdalsjökull (Katla)
2026-06-07 15:58	M1.1	4.2	Mýrdalsjökull (Katla)
2026-06-07 14:19	M-0.1	5.2	Mýrdalsjökull (Katla)
2026-06-07 14:03	M1.7	1.4	Mýrdalsjökull (Katla)
2026-06-07 14:03	M1.5	3.8	Mýrdalsjökull (Katla)
2026-06-07 13:52	M-0.3	5.2	Mýrdalsjökull (Katla)

For the advanced — expert charts — Coulomb, migration, InSAR

🔬 Coulomb stress transfer — advanced analysis

1 earthquakes M≥3.0 in this window on this system. Such events transfer stress to neighbouring faults — some become more likely to slip, others less ("Coulomb stress transfer"). The Met Office does not publish focal mechanisms for automatically located events, so Skjálfti does not compute this itself — it requires strike/dip/rake data which is only available for M≥4.5 events in the GCMT catalogue.

For Coulomb analysis, see: USGS Coulomb 3.4 (stand-alone software) and focal mechanisms for Iceland in Global CMT.

System journal

Automatic snapshots and media coverage, in chronological order. Subscribe: RSS · ntfy skjalftar-katla-myrdalsjokull

2026-06-09 18:00:05 UTC

In the last 24 hours, 14 earthquakes were recorded at Katla, indicating activity similar to the past week and within normal levels for this area. The seismicity is characterized by distributed background activity rather than swarms, and these results are automatic preliminary findings. GNSS data indicate subsidence of approximately 14 mm/year after seasonal correction. Further details on trends and measurements are available below.

2026-06-08 21:40:04 UTC

In the last 24 hours, 15 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The increase is primarily due to distributed background seismicity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data indicate subsidence of approximately 15 mm/year after seasonal correction, though the data are several weeks old. These figures are automatic preliminary results, and further details are available below.

2026-06-08 19:20:04 UTC

In the last 24 hours, 17 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The seismicity is characterized by distributed background activity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data indicate subsidence of approximately 15 mm/year after seasonal correction, though the data are several weeks old. These automatic preliminary results are based solely on numerical measurements without interpretation of causes.

2026-06-08 11:00:06 UTC

In the last 24 hours, seismic activity at Katla has been similar to the past week but slightly higher than usual for this area, characterized mainly by distributed background activity rather than swarms. The largest earthquake was magnitude M2.5 with a cumulative moment of Mw 2.6 over the last 48 hours, while GNSS data indicate subsidence of approximately 15 mm/year. These automatic preliminary results most closely resemble the activity period around October 23, 2025, and further details are available below.

2026-06-07 22:00:06 UTC

In the last 24 hours, 27 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around October 23, 2025. The largest earthquake was M2.5 with a cumulative moment of Mw 2.6 in the last 48 hours, while GNSS data suggest subsidence of ~15 mm/year. These figures are automatic preliminary results, and further details are available below.

2026-06-07 08:50:05 UTC

In the last 24 hours, 16 earthquakes were recorded at Katla, indicating activity similar to the past week and within normal levels for this area. The seismicity is characterized by distributed background activity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data indicate subsidence of approximately 15 mm per year after seasonal correction. These results are automatic preliminary results, and further details are available below.

2026-06-07 04:15:05 UTC

In the last 24 hours, 19 earthquakes were detected at Katla, indicating activity similar to the past week and within normal levels for this area. The seismicity is characterized by distributed background activity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data indicate subsidence of approximately 15 mm/year after seasonal correction, though these data are several weeks old. These figures are automatic preliminary results, and further details are available below.

2026-06-06 23:00:08 UTC

In the last 24 hours, 25 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The increase consists mainly of distributed background activity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data show subsidence of approximately 14 mm/year after seasonal correction, though the data are several weeks old. These figures are automatic preliminary results, and further details are available below.

2026-06-06 13:15:07 UTC

In the last 24 hours, 18 earthquakes were recorded in the Katla volcanic system, indicating activity similar to the past week and within normal levels for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data indicate subsidence of approximately 14 mm/year after seasonal correction, though the data are several weeks old. These figures are automatic preliminary results, and further details are available below.

2026-06-06 04:55:05 UTC

In the last 24 hours, 15 earthquakes were recorded at Katla, indicating higher activity than usual for this area although levels remain similar to the past week. The activity is characterized by distributed background seismicity rather than swarms, with the largest event being M2.6 and a cumulative magnitude of Mw 2.8. GNSS data indicate subsidence of approximately 14 mm/year, though these data are several weeks old and results are automatic preliminary estimates. Further details on trends and measurements can be found below.

2026-06-04 23:00:13 UTC

In the last 24 hours, 17 earthquakes were recorded in the Katla volcanic system, indicating activity similar to the past week and within normal levels for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around October 23, 2025. GNSS data indicate subsidence of approximately 13 mm/year, though the data are several weeks old. These results are automatic preliminary results, and further details are available below.

2026-06-04 13:25:09 UTC

In the last 24 hours, 14 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around September 1, 2025. The cumulative magnitude of the largest earthquakes in the last 48 hours was Mw 2.0, and GNSS data indicate subsidence of ~13 mm/year. These figures are automatic preliminary results, and further details are available below.

2026-06-03 14:55:14 UTC

In the last 24 hours, 22 earthquakes were recorded at Katla, representing an increase compared to the weekly average but remaining within normal levels for this area. The activity consists mainly of distributed background seismicity rather than swarms, with the largest event being magnitude M1.8 at uncertain depth according to automatic preliminary results. GNSS data indicate subsidence of approximately 12 mm per year after seasonal correction, though the data are several weeks old. Activity most closely resembles the period around September 1, 2025, and further details are available below.

2026-06-02 18:10:19 UTC

In the last 24 hours, 12 earthquakes were recorded at Katla, indicating slightly higher activity than usual for this area, though the trend remains similar to the past week. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around August 31, 2025. The cumulative magnitude of the largest earthquakes in the last 48 hours was Mw 2.1, with a b-value of 2.9. These figures are automatic preliminary results, and further data can be found below.

2026-06-02 15:40:16 UTC

In the last 24 hours, 14 earthquakes were recorded at Katla, indicating slightly higher activity than usual for this area although similar to the past week. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around August 31, 2025. The largest earthquake was M2.4 with a cumulative magnitude of Mw 2.5 over the last 48 hours, based on automatic preliminary results. Further details on trends and maps are available below.

2026-06-02 10:30:18 UTC

In the last 24 hours, 16 earthquakes were recorded in the Katla volcanic system, representing an increase from the weekly average but remaining within normal levels for this area. The increase is primarily due to distributed background activity rather than distinct swarms and most closely resembles the period around September 22, 2025. The largest earthquake was magnitude M2.4, with a cumulative moment of Mw 2.5 over the past 48 hours. These figures are automatic preliminary results, and further details are available below.

2026-06-02 03:25:10 UTC

In the last 24 hours, 15 earthquakes were recorded at Katla, representing an increase above the weekly average and higher activity than usual for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around September 22, 2025. The largest earthquake was M2.4 with a cumulative magnitude of Mw 2.5 over 48 hours; these are automatic preliminary results. Further charts and maps are available below.

2026-06-02 00:00:26 UTC

In the last 24 hours, 13 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around September 18, 2025. The largest earthquake was M2.4 with a cumulative moment of Mw 2.5 over the last 48 hours, based on automatic preliminary results. Further charts and maps are available below.

2026-06-01 21:45:10 UTC

In the last 24 hours, 13 earthquakes were recorded in the Katla volcanic system, indicating activity similar to the past week and within normal levels for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around September 7, 2025. The largest earthquake was magnitude M2.4, with a cumulative moment of Mw 2.5 over the last 48 hours. These results are automatic preliminary results.

2026-06-01 13:47:09 UTC

In the last 24 hours, 10 earthquakes were recorded at Katla, indicating activity similar to the past week but slightly higher than usual for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around September 18, 2025. The largest earthquake was M2.4 with a cumulative magnitude of Mw 2.5 over the last 48 hours, based on automatic preliminary results. Further details on trends and measurements are available below.

What do the numbers mean — and what should I do?

β (swarm signal): how high activity is versus the area's 2-year average. β above 2 means an ongoing swarm. It measures activity, not a forecast of a large quake.

Cumulative moment (Mw): the combined energy of the quakes in the period. Uplift (GNSS): whether the ground is rising or sinking, mm per year — the data are a few weeks old. Some systems (e.g. Svartsengi) deform in steps during eruption cycles rather than at a steady annual rate.

Swarm character is computed for a whole volcanic belt, not a single system — it describes the belt, not necessarily this one system.

What should I do? This is automatic monitoring for information — not an official warning. Follow official information from the Icelandic Met Office and Civil Protection (112).

Data: Icelandic Met Office (Skjálftalísa API), automatic preliminary results — may change. This is not an official warning. Official warnings: vedur.is and Civil Protection (112).