Prestahnúkur

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

Status (automatic)

In the last 24 hours, 11 earthquakes were recorded in the Prestahnúkur system and activity is decreasing compared to the weekly average, although it remains higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background activity and most closely resembles the period around May 11, 2026. The largest earthquake in the last 48 hours was M1.7 and the cumulative magnitude was Mw 2.2. Results are automatic preliminary results and further data can be found below.

Depth — 3D and cross-section Prestahnúkur · last 90 days

Each dot is an earthquake, depth as the third dimension — Prestahnúkur, 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 — ~1126 years ago

Hallmundarhraun (around 880–920) (~900). A large shield eruption at the northern end of the system shortly after settlement produced Hallmundarhraun, which covers about 240 km² and contains the Surtshellir lava cave; the lava flowed more than 50 km west.

Volcanic system on the southwestern edge of Langjökull in the Western Volcanic Zone. The central volcano is a rhyolite tuya. No eruptions in historical time; among the least active systems in Iceland. (overview — more at vedur.is) · circle on the map = rough outline of the system (radius).

📜 Did you know?

The central volcano Prestahnúkur is a rhyolite tuya that erupted up through the Ice Age glacier tens of thousands of years ago — a flat-topped peak that records the ice thickness at the time. A silicic (rhyolite) central volcano is unusual in the Western Volcanic Zone, which is otherwise mostly basaltic. No eruptions in historical time, and the system is among the least studied in Iceland.

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

M1.7

M3,0+

Depth range

1–16 km

Earthquakes over time

Cumulative count · 11 earthquakes · total moment ≈ M2.1 · 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

Largest

M1.7

M3,0+

Depth range

0–25 km

Earthquakes over time

Cumulative count · 26 earthquakes · total moment ≈ M2.2 · 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

532

Largest

M3.9

M3,0+

Depth range

0–28 km

Earthquakes over time

Cumulative count · 532 earthquakes · total moment ≈ M4.1 · count moment

No significant hypocenter migration — activity is stationary (R²=0.01, n=532); 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.

Gutenberg-Richter b ≈ 1.27 ± 0.19 (i.e. likely 1.08–1.46, M≥1.7, n=77)

Earthquakes

792

Largest

M3.9

M3,0+

Depth range

0–28 km

Earthquakes over time

Cumulative count · 792 earthquakes · total moment ≈ M4.1 · 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.

Gutenberg-Richter b ≈ 1.41 ± 0.19 (i.e. likely 1.22–1.60, M≥1.7, n=101)

Earthquakes

925

Largest

M3.9

M3,0+

Depth range

0–28 km

Earthquakes over time

Cumulative count · 925 earthquakes · total moment ≈ M4.1 · 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.

Gutenberg-Richter b ≈ 1.50 ± 0.19 (i.e. likely 1.31–1.69, M≥1.7, n=116)

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

1120

Largest

M3.9

M3,0+

Depth range

0–28 km

Earthquakes over time

Cumulative count · 1120 earthquakes · total moment ≈ M4.1 · 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.

Gutenberg-Richter b ≈ 1.49 ± 0.17 (i.e. likely 1.31–1.66, M≥1.7, n=125)

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 →

Earthquakes in the system

Time (UTC)	Mag	Depth	Area
2026-06-10 02:33	M0.8	0.7	Önnur svæði
2026-06-10 01:41	M1.2	5.0	Önnur svæði
2026-06-09 23:12	M1.1	5.2	Langjökull
2026-06-09 21:13	M1.0	1.4	Önnur svæði
2026-06-09 19:23	M1.4	4.9	Langjökull
2026-06-09 19:21	M1.7	3.4	Langjökull
2026-06-09 19:21	M1.7	6.0	Langjökull
2026-06-09 17:16	M1.0	5.5	Önnur svæði
2026-06-09 14:56	M1.2	1.1	Önnur svæði
2026-06-09 10:51	M1.5	7.9	Langjökull
2026-06-09 10:50	M1.1	16.4	Önnur svæði
2026-06-09 06:08	M1.3	7.6	Langjökull
2026-06-09 06:08	M1.4	3.2	Langjökull
2026-06-09 05:55	M1.2	10.2	Önnur svæði
2026-06-09 04:57	M1.4	17.3	Langjökull
2026-06-09 03:05	M1.2	5.2	Langjökull
2026-06-09 02:26	M1.3	5.9	Langjökull
2026-06-09 02:08	M1.1	14.9	Langjökull
2026-06-08 23:58	M1.2	1.1	Önnur svæði
2026-06-08 23:58	M1.2	0.0	Önnur svæði
2026-06-08 21:48	M0.8	24.6	Langjökull
2026-06-08 20:59	M0.8	0.0	Önnur svæði
2026-06-08 20:44	M1.1	0.7	Önnur svæði
2026-06-08 18:46	M0.8	13.2	Önnur svæði
2026-06-08 15:14	M1.2	1.1	Önnur svæði
2026-06-08 15:04	M1.1	1.1	Önnur svæði
2026-06-08 09:02	M1.3	5.5	Langjökull
2026-06-08 06:32	M0.9	2.3	Langjökull
2026-06-08 03:33	M1.3	1.0	Önnur svæði
2026-06-08 03:33	M1.1	1.0	Önnur svæði
2026-06-08 02:39	M1.1	16.7	Langjökull
2026-06-08 02:39	M1.2	5.2	Langjökull
2026-06-07 18:27	M0.4	17.4	Önnur svæði
2026-06-07 15:13	M1.5	2.7	Langjökull
2026-06-07 15:13	M1.4	1.8	Langjökull
2026-06-07 14:58	M1.6	20.0	Langjökull
2026-06-07 14:58	M0.9	0.0	Langjökull
2026-06-07 14:31	M1.2	19.8	Langjökull
2026-06-07 10:00	M1.4	5.2	Langjökull
2026-06-07 08:37	M1.1	5.0	Önnur svæði
2026-06-07 08:18	M1.2	4.9	Önnur svæði
2026-06-07 08:18	M1.5	5.2	Langjökull
2026-06-07 06:44	M0.7	13.7	Langjökull
2026-06-07 06:10	M1.1	8.4	Önnur svæði
2026-06-07 06:10	M1.1	10.9	Langjökull
2026-06-07 06:09	M1.1	13.5	Langjökull
2026-06-07 06:09	M0.3	17.8	Langjökull
2026-06-07 04:51	M1.1	5.2	Önnur svæði
2026-06-07 03:44	M1.1	5.2	Önnur svæði
2026-06-07 03:42	M1.2	1.9	Önnur svæði
2026-06-07 03:40	M1.0	12.2	Langjökull
2026-06-07 01:53	M1.2	5.2	Langjökull
2026-06-06 22:06	M1.1	1.1	Önnur svæði
2026-06-06 21:37	M1.1	14.4	Önnur svæði
2026-06-06 21:37	M0.9	2.6	Önnur svæði
2026-06-06 20:38	M1.1	4.9	Önnur svæði
2026-06-06 20:25	M0.7	15.3	Langjökull
2026-06-06 19:27	M0.5	18.0	Önnur svæði
2026-06-06 19:01	M1.2	5.2	Langjökull
2026-06-06 18:49	M0.9	19.0	Langjökull

System journal

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

2026-06-10 06:00:06 UTC

In the last 24 hours, 12 earthquakes were recorded in the Prestahnúkur system, a rhyolitic tuya and one of the least active systems in the country, where activity is now decreasing although still higher than usual for this area. The recent increase has consisted mostly of short-lived swarms rather than distributed background seismicity, with the largest earthquake in the past 48 hours measuring M1.7 and a cumulative moment of Mw 2.2. These figures are automatic preliminary results and most closely resemble the activity period around May 11, 2026, while further details on trends are available below.

2026-06-10 03:20:04 UTC

In the last 24 hours, 14 earthquakes were recorded in the Prestahnúkur system and activity is decreasing although it remains higher than usual for this area. The increase is mostly due to short-lived swarms rather than distributed background activity, with the largest earthquake at M1.7 and a cumulative magnitude of Mw 2.3 in the past 48 hours. This automatic preliminary result most closely resembles the period around May 11, 2026, in terms of event frequency. Further details on trends and measurements are available below.

2026-06-09 09:10:05 UTC

In the last 24 hours, 13 earthquakes were recorded in the Prestahnúkur system, indicating higher than usual activity for this area although it is decreasing compared to the weekly rate. The increase consists mostly of short-lived swarms and resembles the period around July 7, 2024, while the system remains one of the least active in the country. The cumulative magnitude over the last 48 hours was Mw 2.2 with a b-value of 1.39 +/- 0.18, and results are automatic preliminary results. Further charts and maps are available below.

2026-06-09 05:00:05 UTC

In the last 24 hours, 12 earthquakes were recorded in the Prestahnúkur system, indicating higher than usual activity for this area although it is decreasing compared to the weekly rate. The increase consists mostly of short-lived swarms and resembles the period around July 7, 2024, but the system remains one of the least active in the country. The cumulative magnitude over the last 48 hours was Mw 2.2 and the b-value is 1.39 +/- 0.18. Results are automatic preliminary results and further data can be found below.

2026-06-09 02:15:04 UTC

In the last 24 hours, 13 earthquakes were recorded in the Prestahnúkur system, indicating higher than usual activity for this area although it is decreasing compared to the weekly average. The increase consists mostly of short-lived swarms and resembles the period around July 7, 2024, but the system remains one of the least active in the country. The cumulative magnitude of the largest events in the last 48 hours was Mw 2.2 and the b-value was measured at 1.39. These figures are automatic preliminary results and further data can be found below on the page.

2026-06-09 00:00:11 UTC

In the last 24 hours, 11 earthquakes were recorded in the Prestahnúkur system and activity is decreasing although it remains higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background activity and most closely resembles the period around July 7, 2024. The largest earthquake in the last 48 hours was M1.6 and the cumulative magnitude was Mw 2.2. These figures are automatic preliminary results and further data can be found lower on the page.

2026-06-08 20:50:04 UTC

In the last 24 hours, nine earthquakes were recorded in the Prestahnúkur system, a rhyolitic tuya and one of the least active volcanic systems in the country; activity is now decreasing but remains higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background seismicity and most closely resembles the period around July 7, 2024. The cumulative magnitude of the largest events in the past 48 hours was Mw 2.2, with a b-value of 1.39 +/- 0.18. These results are automatic preliminary findings, and further data can be viewed below.

2026-06-08 18:30:04 UTC

In the last 24 hours, eight earthquakes were recorded in the Prestahnúkur system, a rhyolitic tuya and one of the least active systems in the country, where activity is now decreasing although still higher than usual for this area. The recent increase is primarily due to short-lived swarms rather than distributed background seismicity and most closely resembles the period around July 7, 2024. These figures are automatic preliminary results, and further details on trends can be found below.

2026-06-08 14:35:04 UTC

In the last 24 hours, 11 earthquakes were recorded in the Prestahnúkur system and activity is decreasing compared to the weekly rate, although it remains higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background activity and resembles a period around July 7, 2024. The cumulative magnitude of the largest events in the last 48 hours was Mw 2.3 and the b-value is 1.39 +/- 0.18. Results are automatic preliminary results and further data can be found lower on the page.

2026-06-08 08:20:14 UTC

In the last 24 hours, 13 earthquakes were recorded in the Prestahnúkur system and activity is decreasing although it remains higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background activity, with the largest earthquake at M1.7 and a cumulative magnitude of Mw 2.4 in the past 48 hours. This activity most closely resembles the period around July 7, 2024, but results are automatic preliminary results. Further charts and maps are available below.

2026-06-07 23:15:06 UTC

In the last 24 hours, 20 earthquakes were recorded in the Prestahnúkur system, a rhyolitic tuya and one of the least active systems in the country, with activity now decreasing though still higher than usual for this area. The increase is mostly due to short-lived swarms rather than distributed background seismicity and most closely resembles the period around July 7, 2024. The cumulative magnitude over the past 48 hours is Mw 2.5 and the b-value is 1.39 +/- 0.18. Results are automatic preliminary results, and further data can be found below.

2026-06-07 19:10:06 UTC

In the last 24 hours, 25 earthquakes were recorded in the Prestahnúkur system and activity is decreasing although it remains higher than usual for this area. The increase is mostly due to short-lived swarms, with the largest earthquake in the last 48 hours being M2.2 and a cumulative magnitude of Mw 2.8. This automatic preliminary result most closely resembles the period around July 7, 2024, in terms of event count. Further charts and maps are available below.

2026-06-06 00:00:15 UTC

In the last 24 hours, 134 earthquakes were recorded in the Prestahnúkur system and activity is increasing, which is higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background activity and resembles the period around July 7, 2024. The largest earthquake was M2.7 with a cumulative moment of Mw 3.3 over the past 48 hours, and the b-value is 1.35 +/- 0.18. These figures are automatic preliminary results, and further data can be found below.

2026-06-05 21:35:08 UTC

In the last 24 hours, 110 earthquakes were recorded in the Prestahnúkur system, representing unusually high activity for this area but similar to the past week. The increase consists mostly of short-lived swarms, with the largest event being M3.9 and a cumulative magnitude of Mw 4.0 over the last 48 hours. Activity most closely resembles the period around July 7, 2024, though results are automatic preliminary data. Further details on trends and maps are available below.

2026-06-05 05:45:12 UTC

In the last 24 hours, 103 earthquakes were recorded in the Prestahnúkur system, a rhyolitic tuya and one of the least active systems in the country, but activity is now increasing and higher than usual for this area. The increase consists mostly of short-lived swarms rather than distributed background activity and most closely resembles the period around July 7, 2024. The cumulative magnitude over the last 48 hours is Mw 4.0 and the b-value is 1.29 +/- 0.19. These figures are automatic preliminary results, and further data can be found below on the page.

2026-06-05 01:42:47 UTC

In the last 24 hours, 163 earthquakes were recorded in the Prestahnúkur system, representing unusually high activity for this area and an increase from previous levels. The increase consists mostly of short-lived swarms rather than distributed background activity, with the largest event being M3.9 and a cumulative magnitude of Mw 4.0. This activity most closely resembles the period around July 7, 2024, though results are automatic preliminary results. Further charts and maps 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).